Importance Validation of protein biomarkers for concussion diagnosis and management in military combative training is important, as these injuries occur outside of traditional health care settings and are generally difficult to diagnose. Objective To investigate acute blood protein levels in military cadets after combative training-associated concussions. Design, Setting, and Participants This multicenter prospective case-control study was part of a larger cohort study conducted by the National Collegiate Athletic Association and the US Department of Defense Concussion Assessment Research and Education (CARE) Consortium from February 20, 2015, to May 31, 2018. The study was performed among cadets from 2 CARE Consortium Advanced Research Core sites: the US Military Academy at West Point and the US Air Force Academy. Cadets who incurred concussions during combative training (concussion group) were compared with cadets who participated in the same combative training exercises but did not incur concussions (contact-control group). Clinical measures and blood sample collection occurred at baseline, the acute postinjury point (<6 hours), the 24- to 48-hour postinjury point, the asymptomatic postinjury point (defined as the point at which the cadet reported being asymptomatic and began the return-to-activity protocol), and 7 days after return to activity. Biomarker levels and estimated mean differences in biomarker levels were natural log (ln) transformed to decrease the skewness of their distributions. Data were collected from August 1, 2016, to May 31, 2018, and analyses were conducted from March 1, 2019, to January 14, 2020. Exposure Concussion incurred during combative training. Main Outcomes and Measures Proteins examined included glial fibrillary acidic protein, ubiquitin C-terminal hydrolase-L1, neurofilament light chain, and tau. Quantification was conducted using a multiplex assay (Simoa; Quanterix Corp). Clinical measures included the Sport Concussion Assessment Tool-Third Edition symptom severity evaluation, the Standardized Assessment of Concussion, the Balance Error Scoring System, and the 18-item Brief Symptom Inventory. Results Among 103 military service academy cadets, 67 cadets incurred concussions during combative training, and 36 matched cadets who engaged in the same training exercises did not incur concussions. The mean (SD) age of cadets in the concussion group was 18.6 (1.3) years, and 40 cadets (59.7%) were male. The mean (SD) age of matched cadets in the contact-control group was 19.5 (1.3) years, and 25 cadets (69.4%) were male. Compared with cadets in the contact-control group, those in the concussion group had significant increases in glial fibrillary acidic protein (mean difference in ln values, 0.34; 95% CI, 0.18-0.50; P < .001) and ubiquitin C-terminal hydrolase-L1 (mean difference in ln values, 0.97; 95% CI, 0.44-1.50; P < .001) levels at the acute postinjury point. The glial fibrillary acidic protein level remained high in the concussion group compared with the contact-control group at the 24- to 48-hour postinjury point (mean difference in ln values, 0.22; 95% CI, 0.06-0.38; P = .007) and the asymptomatic postinjury point (mean difference in ln values, 0.21; 95% CI, 0.05-0.36; P = .01). The area under the curve for all biomarkers combined, which was used to differentiate cadets in the concussion and contact-control groups, was 0.80 (95% CI, 0.68-0.93; P < .001) at the acute postinjury point. Conclusions and Relevance This study's findings indicate that blood biomarkers have potential for use as research tools to better understand the pathobiological changes associated with concussion and to assist with injury identification and recovery from combative training-associated concussions among military service academy cadets. These results extend the previous findings of studies of collegiate athletes with sport-associated concussions. ; Grand Alliance Concussion Assessment, Research, and Education Consortium; National Collegiate Athletic Association; US Department of DefenseUnited States Department of Defense; Office of the Assistant Secretary of Defense for Health Affairs [W81XWH-14-2-0151] ; This study was supported by the Grand Alliance Concussion Assessment, Research, and Education Consortium, the National Collegiate Athletic Association, the US Department of Defense, and grant W81XWH-14-2-0151 from the Office of the Assistant Secretary of Defense for Health Affairs through the Psychological Health and Traumatic Brain Injury Program.
AbstractThis paper characterizes the Canadian investment opportunity set (IOS) over the period from 1967 through 1993. The conditional IOS represents the risk and return choices available to investors based on estimated conditional means and dispersions for equities, bills, bonds, and real estate. Our analysis reveals a number of insights regarding the evolution of conditional asset moments in relation to important macrofinancial factors. We consider the impact of the term structure, the strength of the Canadian dollar relative to the U. S. dollar, the January effect, as well as other time series measures in our specification for conditional expected returns and risks. Our conditional mean specification finds strong sensitivities to economic factors as well as to time series factors in the debt equations. A substantial January effect is found only in conditional equity moments. Conditional risks display strong time series properties as well as economic sensitivities to changes in short rates and to the short yield. After characterizing the evolution of asset risks over time, we construct the conditional efficient set constants that describe the conditional Canadian IOS hyperbole. We find that the estimated IOS has a much larger maximum risk price (slope) than is typically observed in unconditional estimates. The use of additional information reduces conditional portfolio risk substantively. From a time series perspective, the estimated slope is always positive, is positively serially correlated, and is significantly nonnormal (with substantial right skewness and leptokurtism). Ignoring other influences, we find a strong simple correlation between the riskless rate (IOS vertex) and the risk price (IOS slope); however, our economic instruments display strong collinearity. We observe the following empirical regularities regarding IOS slope behaviour: a one time increase in short‐term interest rates reduces the price of risk, an increase in long term bond yields results in an increase in the required market risk price, and the market price of risk increases substantially in January.RésuméDans le présent article, nous étudions l'ensemble des opportunités de placement (EOP) canadien pendant la période de 1967 à 1993. L'EOP conditionnel représente les arbitrages de risque et de rendement disponibles pour les investisseurs, fondés sur les moyennes et écarts conditionnels du rendement des actions, des bons du Trésor, des obligations et des propriétés immobilières. Notre analyse donne un aperçu général de l'évolution des moments des actifs conditionnels en relation avec des facteurs macro‐financiers importants. Nous nous penchons sur l'impact de la structure à terme des taux d'intérět, de la valeur du dollar canadien par rapport au dollar américain, de l'effet janvier et d'autres facteurs économiques ainsi que des facteurs temps dans notre spécification de rendement et de risque conditionnels anticipés. Notre spécification moyenne conditionnelle est largement influencée par les facteurs économiques ainsi que par les facteurs temps dans l'équation de la dette. Il existe un effet janvier substantiel seulement dans des moments conditionnels du rendement des actions. Des risques conditionnels montrent des propriétés chronologiques importantes ainsi qu'une sensibilitéaux changements dans les placements à court terme et dans les rendements à court terme. Après avoir précisé l'évolution des risques des actions dans le temps, on construit des constantes conditionnelles de l'ensemble efficient qui décrivent l'hyperbole canadienne de l'EOP. Nos résultats montrent que l'EOP estimatif comporte un prix de risque maximum (pente) bien plus élevéque celui observé généralement par les estimatifs inconditionnels. L'utilisation d'informations additionnelles réduit substantiellement le risque conditionnel du portefeuille. Du point de vue chronologique, la pente estimative, de měme que la corrélation, est toujours positive et non normale (avec une asymétrie exacte et un leptokurtisme importants). En laissant de cǒtétoutes les influences, on trouve une corrélation importante et simple entre le facteur sans risque (sommet de l'EOP) et le prix de risque (pente EOP); pourtant, nos instruments économiques montrent une collinéarité notable. On observe les régularités empiriques suivantes en ce qui concerne le comportement de la pente EOP: l'accroissement unique du taux d'intérět à court terme réduit le prix de risque et celui des obligations à long terme augmente le prix de risque du marché exigépar ailleurs, le risque financier du marché augmente énonnément en janvier.
Chapter 1 (Energy Use Patterns in German Industry: Evidence from Plant-level Data): This paper analyzes energy use and CO2 emissions of more than 78 000 German industrial plants between 1995 and 2006. It is the first study to exploit exceptionally rich energy data that were recently matched to official micro datasets. We document that both energy use and intensity are highly dispersed across plants. When isolating the between-sector variation in energy intensity, there is a strong positive correlation with energy use, CO2 emissions and emission intensity. Yet there is no evidence that the scale of an industry determines its energy intensity. The dispersion of energy use across plants of a given sector, normalized by the median, is positively correlated with that of gross output, but not with the median energy use. Similarly, there is no evidence that the median energy intensity is correlated with the within-sector dispersion of energy intensity or with that of CO2 emissions. Looking at the fuel mix across sectors, we find that more energy intensive industries rely more on fuels other than electricity, although the variability among plants in those industries is extremely high. We also demonstrate that average fuel shares are sensitive to the skewness of the underlying distribution and recommend the use of median fuel shares for better representativeness. Chapter 2 (Carbon Efficiency, Technology, and the Role of Innovation Patterns: Evidence from German Plant-Level Microdata): We describe the determinants of energy intensity, carbon intensity, and CO2 emissions in the German manufacturing sector between 1995 and 2007, applying the LMDI index decomposition technique to micro data. We decompose changes in total CO2 emissions from manufacturing to changes in activity level, structural change between sectors, shifting market shares within sectors, energy intensity at the firm level, fuel mix, and emission factors. Our results show that competition between firms within one sector, although so far widely ignored as a driver of emissions and energy use, is energy- and emission-saving. Contrary to wide-spread beliefs, energy intensity improvements at the firm level do not play a significant role in reducing emissions. We use sector-level results on the relative importance of improvements in firm-level energy intensity and intra-sectoral structural change to distinguish two different innovation channels: innovation by technology and by entrants. We show that incumbent firms in a number of sectors, including some of the most energy intensive, do not significantly improve their energy efficiency. Innovation takes place via new entrants instead, rendering policies targeted at incumbents' firm-level energy efficiency ineffective. Chapter 3 (The Impact of Carbon Trading on Industry: Evidence from German Manufacturing Firms): We estimate the causal impact of the EU Emissions Trading Scheme on manufacturing firms using comprehensive panel data from the German production census. Semiparametric matching estimators yield robust evidence that the policy caused treated firms to abate one-fifth of their CO2 emissions between 2007 and 2010 relative to non-treated firms. This reduction was achieved predominantly by improving energy efficiency and by curbing the consumption of natural gas and petroleum products, but not electricity use. We find no evidence that emissions trading lowered employment, gross output or exports of treated firms. Chapter 4 (The Impact of Temperature Changes on Residential Energy Consumption): In order to explore the impact of climate change on energy use, we estimate an energy demand model that is driven by temperature, prices and income. The estimation is based on an unbalanced panel of 62 countries over three decades. We limit the analysis to the residential sector and distinguish four different fuel types (coal, electricity, natural gas and oil). Compared to previous papers, we have a better geographical coverage and consider both a heating and cooling threshold as well as further non-linearities in the impact of temperature on energy demand and temperature-income interactions. We find that oil, gas and electricity use are driven by a non-linear heating effect: Energy use decreases with rising temperatures due to a reduced demand for energy for heating purposes, but the speed of that decrease declines with rising temperature levels. We cannot find a significant impact of temperature on the demand for cooling energy.
In a context where both academic institutions and government consider academic excellence as crucial, this thesis aims at contributing to the study of the determinants of scientific productivity of professors. Using an original database of French academic economists involved in the "Prime d'Excellence Scientifique" tournament, the four proposed contributions show the importance of considering two dimensions often ignored so far: first, collective externalities, and the multidimensional nature of professors' activities.The first chapter investigates the determinants of success in a large competition among French academic economists, the "Prime d'Excellence Scientifique (PES)". We are particularly interested in the dynamic aspects of this repeated tournament initiated by the French academic system in 2009 to select the best productive researchers for promotion. The econometric estimation of the transition probabilities using sequential-response models allows for identification of changes in weightings assigned to each criterion. Our results confirm the importance of peer-reviewed publications and identify discouraging factors in this dynamic tournament. We also find that past success influences the promotion of professors.The second chapter focuses on the most decisive factor in the award of the "Prime d'Excellence Scientifique": the scientific production. It shows that the scientific environment can explain both the path dependency in individual scientific productivity and the high inequality and skewness of individual productivity distributions. The results of quantile regressions show the existence of two separated regimes of scientific production, namely the regime of specialists and the regime of generalists. Our results also show that life-cycle effects are not only significant for the evaluation of individual productivity scores but also for the stock of knowledge accumulated in economics departments.Taking into account the potential interactions between teaching and research activities highlighted in the second chapter, the third chapter investigates the determinants of scientific production, including collective determinants related to the research environment, in the context of multitasking teachers. The chapter develops a principal-agent model to understand how university professors allocate their time between two substitutable tasks: publishing and teaching. The theoretical model predicts that professors devote more time to the tasks for which they have a marginal advantage. Controling for endogeneity activity choices, the econometric analysis confirm the key predictions ofthe model: these tasks are conflicting and the institutional context affects the activity choices of professors.Based on the heterogeneity of publication outlets, the fourth chapter analyzes the determinants of the quantity-quality tradeoff in scientific production. The focus is on the determinants of two types of publications identified by the journals ranking in Economics of the French National Committee for Scientific Research (CNRS): publications in high-quality journals and publications in low quality journals. The joint estimates of these two types of publications indicate that there is a tradeoff between the high quality publications and low quality publications, and this tradeoff is imputable to the scientific environment of professors. Our results confirm a negative impact of teaching and administrative duties on the publications in high quality journals. ; Dans un contexte où la recherche de l'excellence universitaire est au coeur des préoccupations des institutions académiques et des pouvoirs publics, cette thèse a pour objectif de contribuer à l'étude des déterminants de la production scientifique des enseignants-chercheurs français en économie. En mobilisant les données originales issues des candidatures des enseignants-chercheurs à la ''Prime d'Excellence Scientifique'', les quatre contributions proposées s'attachent à articuler deux importantes dimensions, jusqu'ici rarement traitées conjointement par la littérature : les effets d'externalités collectives dans la production scientifique, et le caractère multitâche de l'activité des enseignants-chercheurs. Le premier chapitre de la thèse analyse les déterminants de l'obtention de la Prime d'Excellence Scientifique des enseignants-chercheurs français en économie. Nous nous intéressons au caractère multitâche de la production individuelle et à la dimension dynamique de cette forme particulière de compétition académique mise en place depuis 2009. Les résultats économétriques obtenus à partir d'un modèle séquentiel montrent que les publications scientifiques constituent le facteur le plus déterminant dans les chances de succès à la PES. Nous identifions les facteurs de découragement au cours de ce tournoi dynamique. Les résultats montrent également que la promotion passée au titre du précédent dispositif PEDR augmente les chances de promotion des enseignants-chercheurs. Le second chapitre se penche sur le facteur déterminant de l'attribution de la PES et de la promotion des enseignants-chercheurs : la production scientifique. Ce chapitre met en évidence que les effets d'externalités associés à l'environnement de recherche des enseignants-chercheurs sont susceptibles d'expliquer à la fois la dynamique individuelle de la production scientifique et la concentration de celle-ci entre un petit nombre d'enseignants-chercheurs. Nos résultats économétriques par quantiles concluent à l'existence de deux régimes de production scientifiques extrêmes : les polyvalents et les spécialistes. Toutefois, nos résultats ne réfutent pas l'existence d'un cycle de production scientifique qui serait sensible au stock de compétences accumulées dans l'environnement de travail des enseignants-chercheurs. Tenant compte des interactions potentielles entre les tâches d'enseignement et de recherche mises en évidence dans le second chapitre, le troisième chapitre propose d'analyser à partir d'un modèle théorique et économétrique, les effets de l'environnement de recherche sur le choix d'activités des enseignants-chercheurs. En contrôlant la simultanéité et l'endogénéité du choix des tâches de l'enseignement et de la recherche, les résultats économétriques sur nos données confortent largement les prédictions théoriques : les effets d'externalités issus de la concentration spatiale des compétences en recherche et/ou en formation à un moment donné, conduit à des profils « typés » de spécialistes (en recherche ou en formation) ou à l'opposé de « généralistes » associant production scientifique, implications pédagogiques et responsabilités collectives. Prenant en compte l'hétérogénéité des publications scientifiques en économie, le quatrième chapitre analyse des déterminants de l'arbitrage « quantité-qualité » dans la production scientifique. Nous étudions en particulier les déterminants du choix de deux types publications définies dans le classement CNRS des revues d'économie: les publications de premier rang et les publications de second rang. Les résultats économétriques de l'estimation jointe de ces deux types de publications concluent à un arbitrage entre les publications de bonne qualité et les publications dans les revues moins bien classées, arbitrage sensible aux effets d'externalité de l'environnement de recherche des enseignants-chercheurs.
In a context where both academic institutions and government consider academic excellence as crucial, this thesis aims at contributing to the study of the determinants of scientific productivity of professors. Using an original database of French academic economists involved in the "Prime d'Excellence Scientifique" tournament, the four proposed contributions show the importance of considering two dimensions often ignored so far: first, collective externalities, and the multidimensional nature of professors' activities.The first chapter investigates the determinants of success in a large competition among French academic economists, the "Prime d'Excellence Scientifique (PES)". We are particularly interested in the dynamic aspects of this repeated tournament initiated by the French academic system in 2009 to select the best productive researchers for promotion. The econometric estimation of the transition probabilities using sequential-response models allows for identification of changes in weightings assigned to each criterion. Our results confirm the importance of peer-reviewed publications and identify discouraging factors in this dynamic tournament. We also find that past success influences the promotion of professors.The second chapter focuses on the most decisive factor in the award of the "Prime d'Excellence Scientifique": the scientific production. It shows that the scientific environment can explain both the path dependency in individual scientific productivity and the high inequality and skewness of individual productivity distributions. The results of quantile regressions show the existence of two separated regimes of scientific production, namely the regime of specialists and the regime of generalists. Our results also show that life-cycle effects are not only significant for the evaluation of individual productivity scores but also for the stock of knowledge accumulated in economics departments.Taking into account the potential interactions between teaching and research activities highlighted in the second chapter, the third chapter investigates the determinants of scientific production, including collective determinants related to the research environment, in the context of multitasking teachers. The chapter develops a principal-agent model to understand how university professors allocate their time between two substitutable tasks: publishing and teaching. The theoretical model predicts that professors devote more time to the tasks for which they have a marginal advantage. Controling for endogeneity activity choices, the econometric analysis confirm the key predictions ofthe model: these tasks are conflicting and the institutional context affects the activity choices of professors.Based on the heterogeneity of publication outlets, the fourth chapter analyzes the determinants of the quantity-quality tradeoff in scientific production. The focus is on the determinants of two types of publications identified by the journals ranking in Economics of the French National Committee for Scientific Research (CNRS): publications in high-quality journals and publications in low quality journals. The joint estimates of these two types of publications indicate that there is a tradeoff between the high quality publications and low quality publications, and this tradeoff is imputable to the scientific environment of professors. Our results confirm a negative impact of teaching and administrative duties on the publications in high quality journals. ; Dans un contexte où la recherche de l'excellence universitaire est au coeur des préoccupations des institutions académiques et des pouvoirs publics, cette thèse a pour objectif de contribuer à l'étude des déterminants de la production scientifique des enseignants-chercheurs français en économie. En mobilisant les données originales issues des candidatures des enseignants-chercheurs à la ''Prime d'Excellence Scientifique'', les quatre contributions proposées s'attachent à articuler deux importantes dimensions, jusqu'ici rarement traitées conjointement par la littérature : les effets d'externalités collectives dans la production scientifique, et le caractère multitâche de l'activité des enseignants-chercheurs. Le premier chapitre de la thèse analyse les déterminants de l'obtention de la Prime d'Excellence Scientifique des enseignants-chercheurs français en économie. Nous nous intéressons au caractère multitâche de la production individuelle et à la dimension dynamique de cette forme particulière de compétition académique mise en place depuis 2009. Les résultats économétriques obtenus à partir d'un modèle séquentiel montrent que les publications scientifiques constituent le facteur le plus déterminant dans les chances de succès à la PES. Nous identifions les facteurs de découragement au cours de ce tournoi dynamique. Les résultats montrent également que la promotion passée au titre du précédent dispositif PEDR augmente les chances de promotion des enseignants-chercheurs. Le second chapitre se penche sur le facteur déterminant de l'attribution de la PES et de la promotion des enseignants-chercheurs : la production scientifique. Ce chapitre met en évidence que les effets d'externalités associés à l'environnement de recherche des enseignants-chercheurs sont susceptibles d'expliquer à la fois la dynamique individuelle de la production scientifique et la concentration de celle-ci entre un petit nombre d'enseignants-chercheurs. Nos résultats économétriques par quantiles concluent à l'existence de deux régimes de production scientifiques extrêmes : les polyvalents et les spécialistes. Toutefois, nos résultats ne réfutent pas l'existence d'un cycle de production scientifique qui serait sensible au stock de compétences accumulées dans l'environnement de travail des enseignants-chercheurs. Tenant compte des interactions potentielles entre les tâches d'enseignement et de recherche mises en évidence dans le second chapitre, le troisième chapitre propose d'analyser à partir d'un modèle théorique et économétrique, les effets de l'environnement de recherche sur le choix d'activités des enseignants-chercheurs. En contrôlant la simultanéité et l'endogénéité du choix des tâches de l'enseignement et de la recherche, les résultats économétriques sur nos données confortent largement les prédictions théoriques : les effets d'externalités issus de la concentration spatiale des compétences en recherche et/ou en formation à un moment donné, conduit à des profils « typés » de spécialistes (en recherche ou en formation) ou à l'opposé de « généralistes » associant production scientifique, implications pédagogiques et responsabilités collectives. Prenant en compte l'hétérogénéité des publications scientifiques en économie, le quatrième chapitre analyse des déterminants de l'arbitrage « quantité-qualité » dans la production scientifique. Nous étudions en particulier les déterminants du choix de deux types publications définies dans le classement CNRS des revues d'économie: les publications de premier rang et les publications de second rang. Les résultats économétriques de l'estimation jointe de ces deux types de publications concluent à un arbitrage entre les publications de bonne qualité et les publications dans les revues moins bien classées, arbitrage sensible aux effets d'externalité de l'environnement de recherche des enseignants-chercheurs.
In a context where both academic institutions and government consider academic excellence as crucial, this thesis aims at contributing to the study of the determinants of scientific productivity of professors. Using an original database of French academic economists involved in the "Prime d'Excellence Scientifique" tournament, the four proposed contributions show the importance of considering two dimensions often ignored so far: first, collective externalities, and the multidimensional nature of professors' activities.The first chapter investigates the determinants of success in a large competition among French academic economists, the "Prime d'Excellence Scientifique (PES)". We are particularly interested in the dynamic aspects of this repeated tournament initiated by the French academic system in 2009 to select the best productive researchers for promotion. The econometric estimation of the transition probabilities using sequential-response models allows for identification of changes in weightings assigned to each criterion. Our results confirm the importance of peer-reviewed publications and identify discouraging factors in this dynamic tournament. We also find that past success influences the promotion of professors.The second chapter focuses on the most decisive factor in the award of the "Prime d'Excellence Scientifique": the scientific production. It shows that the scientific environment can explain both the path dependency in individual scientific productivity and the high inequality and skewness of individual productivity distributions. The results of quantile regressions show the existence of two separated regimes of scientific production, namely the regime of specialists and the regime of generalists. Our results also show that life-cycle effects are not only significant for the evaluation of individual productivity scores but also for the stock of knowledge accumulated in economics departments.Taking into account the potential interactions between teaching and research activities highlighted in the second chapter, the third chapter investigates the determinants of scientific production, including collective determinants related to the research environment, in the context of multitasking teachers. The chapter develops a principal-agent model to understand how university professors allocate their time between two substitutable tasks: publishing and teaching. The theoretical model predicts that professors devote more time to the tasks for which they have a marginal advantage. Controling for endogeneity activity choices, the econometric analysis confirm the key predictions ofthe model: these tasks are conflicting and the institutional context affects the activity choices of professors.Based on the heterogeneity of publication outlets, the fourth chapter analyzes the determinants of the quantity-quality tradeoff in scientific production. The focus is on the determinants of two types of publications identified by the journals ranking in Economics of the French National Committee for Scientific Research (CNRS): publications in high-quality journals and publications in low quality journals. The joint estimates of these two types of publications indicate that there is a tradeoff between the high quality publications and low quality publications, and this tradeoff is imputable to the scientific environment of professors. Our results confirm a negative impact of teaching and administrative duties on the publications in high quality journals. ; Dans un contexte où la recherche de l'excellence universitaire est au coeur des préoccupations des institutions académiques et des pouvoirs publics, cette thèse a pour objectif de contribuer à l'étude des déterminants de la production scientifique des enseignants-chercheurs français en économie. En mobilisant les données originales issues des candidatures des enseignants-chercheurs à la ''Prime d'Excellence Scientifique'', les quatre contributions proposées s'attachent à articuler deux importantes dimensions, jusqu'ici rarement traitées conjointement par la littérature : les effets d'externalités collectives dans la production scientifique, et le caractère multitâche de l'activité des enseignants-chercheurs. Le premier chapitre de la thèse analyse les déterminants de l'obtention de la Prime d'Excellence Scientifique des enseignants-chercheurs français en économie. Nous nous intéressons au caractère multitâche de la production individuelle et à la dimension dynamique de cette forme particulière de compétition académique mise en place depuis 2009. Les résultats économétriques obtenus à partir d'un modèle séquentiel montrent que les publications scientifiques constituent le facteur le plus déterminant dans les chances de succès à la PES. Nous identifions les facteurs de découragement au cours de ce tournoi dynamique. Les résultats montrent également que la promotion passée au titre du précédent dispositif PEDR augmente les chances de promotion des enseignants-chercheurs. Le second chapitre se penche sur le facteur déterminant de l'attribution de la PES et de la promotion des enseignants-chercheurs : la production scientifique. Ce chapitre met en évidence que les effets d'externalités associés à l'environnement de recherche des enseignants-chercheurs sont susceptibles d'expliquer à la fois la dynamique individuelle de la production scientifique et la concentration de celle-ci entre un petit nombre d'enseignants-chercheurs. Nos résultats économétriques par quantiles concluent à l'existence de deux régimes de production scientifiques extrêmes : les polyvalents et les spécialistes. Toutefois, nos résultats ne réfutent pas l'existence d'un cycle de production scientifique qui serait sensible au stock de compétences accumulées dans l'environnement de travail des enseignants-chercheurs. Tenant compte des interactions potentielles entre les tâches d'enseignement et de recherche mises en évidence dans le second chapitre, le troisième chapitre propose d'analyser à partir d'un modèle théorique et économétrique, les effets de l'environnement de recherche sur le choix d'activités des enseignants-chercheurs. En contrôlant la simultanéité et l'endogénéité du choix des tâches de l'enseignement et de la recherche, les résultats économétriques sur nos données confortent largement les prédictions théoriques : les effets d'externalités issus de la concentration spatiale des compétences en recherche et/ou en formation à un moment donné, conduit à des profils « typés » de spécialistes (en recherche ou en formation) ou à l'opposé de « généralistes » associant production scientifique, implications pédagogiques et responsabilités collectives. Prenant en compte l'hétérogénéité des publications scientifiques en économie, le quatrième chapitre analyse des déterminants de l'arbitrage « quantité-qualité » dans la production scientifique. Nous étudions en particulier les déterminants du choix de deux types publications définies dans le classement CNRS des revues d'économie: les publications de premier rang et les publications de second rang. Les résultats économétriques de l'estimation jointe de ces deux types de publications concluent à un arbitrage entre les publications de bonne qualité et les publications dans les revues moins bien classées, arbitrage sensible aux effets d'externalité de l'environnement de recherche des enseignants-chercheurs.
This thesis consists of five chapters. The first three chapters form an entity and deal with stochastic contest models. The fourth chapter analyzes a problem of strategic experimentation with private payoffs. In the final chapter the behavior of agents with prospect theory preferences in optimal stopping problems is analyzed. Contests and tournaments appear in many real world situations, like sports, politics, patent races, relative reward schemes in firms, or (public) procurement. In a contest multiple agents compete for a fixed prize. The first two chapters of this dissertation analyze contest models in continuous time. Both are based upon joint work with Christian Seel. In the first two chapters we introduce a new type of contest model. In our model each agent decides when to stop a privately observed Brownian motion with drift. The processes of the different players are uncorrelated. The player who stops with the highest value wins a fixed prize. Each agent observes only his own progress, but not the progress or the stopping decision of the other players. As no deviations are observable we use Nash equilibrium as the solution concept. The model is similar to an all-pay auction with complete information as the payoffs of an agent depend only on the distribution of the stopped values of the Brownian motion of the other players. Hence the question which distributions can be implemented by stopping a Brownian motion naturally arises. This question is known in the probability theory literature as the Skorokhod embedding problem. Using insights from this literature we are able to construct an equilibrium and show uniqueness of the equilibrium outcome. Using a bound on stopping times derived in ? we are able to show in the second chapter that the equilibrium we construct is also the unique equilibrium if the contest ends at a fixed point in time – given this deadline is not to short. This result is important as many real world contests have a fixed deadline. From a technical point of view we provide a method to show that equilibria in an infinite horizon game are also equilibria in the finite horizon game given the time horizon is long enough. The next paragraph describes the applications of the model. The model of the first chapter can be used to analyze the competition between fund managers. Each fund manager decides when to sell a risky asset. The performance of the asset follows a Brownian motion with drift. Assets are uncorrelated among fund managers and might go bankrupt. The fund manager who makes the highest profit by selling his asset wins a fixed prize. We show that the model has unique Nash equilibrium outcome. In this equilibrium the fund managers hold the risky asset even if it yields losses in expectation, i.e. the drift of the Brownian motion is negative. We show that the expected losses incurred in equilibrium by the fund managers are non-monotone in the expected return of the risky asset. Losses are highest if the underlying assets yields only moderate losses. In the last step we analyze the asymmetric situation where two fund managers hold assets with different expected return (drift of the Brownian motion) and riskiness (variance of the Brownian motion). We prove that in the unique Nash equilibrium outcome the weaker fund manager makes up for his disadvantage by using more risky strategies. 1The second chapter focusses on Research and Development Tournaments. Each agent decides for how long to do research and pay the associated cost. The outcome of research is uncertain and described by a Brownian motion with drift. The research progress of different agents is uncorrelated. When all agents stop, the one who made the most progress, wins a prize. All agent have to pay the cost of their research. We assume that there exists a finite deadline at which all agents are forced to stop doing research. We prove that the game has a unique Nash equilibrium outcome. If costs per time are constant, and if the riskiness of the research process (variance of the Brownian motion) converges to zero the equilibrium outcome converges to the symmetric equilibrium outcome of the symmetric all-pay auction. As the symmetric all-pay auction has multiple equilibria, this result provides an equilibrium selection criterion in favor of the symmetric equilibrium. If the variance of the Brownian motion is strictly greater zero, i.e. the outcome of research is uncertain the predictions of our model are different from those of the all-pay auction. In equilibrium each agent makes positive profits, while in the all-pay auction the agents make zero profits. Furthermore we show that the profits of the agents are increasing in their costs and variance and decreasing in the drift. Hence the agents prefer to be in a situation where research is very costly, inefficient, and risky. This has possibly implications for many real world situations as the agents have incentives to make the designer choose inefficient research targets. The third chapter of this dissertation is joint work with Matthias Lang and Christian Seel. It provides a micro-foundation of the discrete-bid all-pay auction using a continuous time contest model. More precisely we analyze the model where each agent decides when to stop a privately observed Poisson process. The processes of the agents are uncorrelated and the stopping decision of other players is not observable. As long as an agent did not stop she pays constant flow cost. There exists a finite deadline where each agent is forced to stop. We show that if the deadline is long enough the distribution over final outcomes in any Nash equilibrium equals the distribution of bids in a discrete-bid all-pay auction. Chapter four is joint work with Paul Heidhues and Sven Rady and deals with a problem of strategic experimentation. Precisely, an optimal stopping game with an infinite time horizon is analyzed in which multiple players face an identical two-armed bandit problem. At all points in time, agents choose between the deterministic payoff of zero and a risky payoff whose distribution depends on the state of the world. In the bad state of the world the risky payoff is always negative, representing the cost of experimentation. If the world is in the good state, with a small probability an experiment is successful and yields a high payoff. Because a success can only happen in the good state of the world, it fully reveals the state of the world. Similar models analyzed in literature show a free-rider problem, which means that less than the socially efficient amount of information is acquired in all Markov perfect equilibria. This free-rider problem is a consequence of the ability of agents to observe each others payoffs, which results in information being a public good. We show that when payoffs are public information even in subgame-perfect equilibria, the ensuing free- rider problem is so severe that the number of experiments is at most one plus the number of experiments that a single agent would perform. When payoffs are private information and players can communicate via cheap talk, the social opti- mal symmetric experimentation profile can be supported as a perfect Bayesian equilibrium for sufficiently optimistic prior beliefs. 2Chapter five deals with optimal stopping under prospect theory preferences and is based upon joint work with Sebastian Ebert. While expected utility theory is the leading normative theory of decision making under risk, cumulative prospect theory is a popular descriptive theory. Expected utility theory is well-studied in both static and dynamic settings, ranging from game theory over investment problems to institutional economics. In contrast, for cumulative prospect theory most research so far has focused on the static case. In this chapter, we investigate cumulative prospect theory's predictions in the dynamic context and point out fundamental properties of cumulative prospect theory. We show that already a small amount of probability weighting has strong implications for the application of prospect theory in the dynamic context. More precisely we analyze the behavior of a naive agent with cumulative prospect theory preferences in continuous time optimal stopping problems. We prove that naive agent will never stop a non-degenerate diffusion process that represents his wealth. This holds for a very large class of processes, and independently of the reference point and the curvatures of the value and weighting functions. This dynamic result is a consequence of a static result that we call skewness preference in the small: At any wealth level there exists an arbitrarily small right-skewed gamble that a prospect theory agent wants to take. By choosing a proper stopping strategy the agent can always implement such a gamble and thus never stops. We illustrate the implications for dynamic decision problems such as irreversible investment, casino gambling, and the disposition effect.
Econometric Modeling provides a new and stimulating introduction to econometrics, focusing on modeling. The key issue confronting empirical economics is to establish sustainable relationships that are both supported by data and interpretable from economic theory. The unified likelihood-based approach of this book gives students the required statistical foundations of estimation and inference, and leads to a thorough understanding of econometric techniques. David Hendry and Bent Nielsen introduce modeling for a range of situations, including binary data sets, multiple regression, and cointegrated systems. In each setting, a statistical model is constructed to explain the observed variation in the data, with estimation and inference based on the likelihood function. Substantive issues are always addressed, showing how both statistical and economic assumptions can be tested and empirical results interpreted. Important empirical problems such as structural breaks, forecasting, and model selection are covered, and Monte Carlo simulation is explained and applied. Econometric Modeling is a self-contained introduction for advanced undergraduate or graduate students. Throughout, data illustrate and motivate the approach, and are available for computer-based teaching. Technical issues from probability theory and statistical theory are introduced only as needed. Nevertheless, the approach is rigorous, emphasizing the coherent formulation, estimation, and evaluation of econometric models relevant for empirical research
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Introduction Choice and access to health care are important determinants of health outcomes. Various issues influence choice and determine the degree of, and differences in access to health care. Choice of health care facilities by individuals is often determined by the interplay between patient and provider characteristics. The influence of factors that determine choice of a health care facility or a provider varies depending on individual patient's socio-ecological factors, type and severity of illness (including the presence or absence of co-morbidities), cost of healthcare (including travel costs), and the presence or absence of a third party such as a health insurance plan. On the other hand, provider or facility factors, which include spatial and non-spatial factors such as technical and functional dimensions of quality of care, are the supply–side factors that influence choice of provider and facility. In order to achieve universal health coverage and attain the Sustainable Development Goals, Nigeria adopted a prepayment health care financing method through the National Health Insurance Scheme (NHIS) in 2005. However, population coverage of the scheme remains very low, while it also has a reputation of less than optimal performance. Evidence showed that while some accredited NHIS facilities were burdened with a high volume of enrolees, others had registered low volume (of enrolees). This study explored the influence and magnitude of the various factors responsible for the poor performance of the scheme as well as the lopsided/uneven distribution of enrolees across these health care facilities. Findings will assist in repositioning the scheme for better performance as well as serve as a guide for other countries planning to design and implement similar schemes. This will enable such schemes to learn from and avoid mistakes made under the present scheme. Methods This study was cross-sectional in design, with descriptive and analytical components. Data were collected using a mixed-method approach (geo-spatial, quantitative and qualitative). The geo-spatial component was achieved using three data layers of x and y coordinates: the enrolees' locations, locations of NHIS facilities and locations of health care facilities typically used by enrolees, were used in the spatial analysis to identify the closest NHIS accredited health care facility to each enrolee's residence and also estimate the distance between enrolee's location and NHIS facility being utilised. The Distance to the Nearest Hub (points) function in Quantum GIS 3.10 was used to automatically assign enrolees to the nearest NHIS facility while the Join by lines (Hub Lines) function was used to assign enrolees to the NHIS facility they used. Spider web diagrams that depict geo-spatial relationship between enrolees' residence, patronised health care facilities and health care facilities closest to the residences were constructed. Quantitative data were collected from 432 NHIS enrolees using an adapted questionnaire. A checklist was also used to collect data on structural components of health facilities such as the number and cadre of the health workforce, availability and functionality of medical equipment and facility infrastructure. Quantitative data were analysed using STATA and frequency tables were generated. Qualitative data were collected through in-depth interviews conducted among 29 participants of the NHIS, HMOs, enrolees, head of facilities and an academic. Qualitative data analysis was done using an inductive thematic approach. Audio-taped interviews were transcribed and codes were generated. Themes were thereafter searched for and generated from the codes. Emerging themes were named, documented and analysed accordingly. A conceptual framework that illustrated the Nigeria contextual environment, the health system and the current governance of the NHIS with a highlight on the relationships, factors and patterns of interaction among stakeholders was designed. Results The majority of the enrolees received care across a small proportion of the accredited facilities and bypassed nearby health facilities to receive care. Almost all the study respondents, 405 (93.9%) bypassed, however, only 147 (34.0%) reported to have done so. In this study, predictors of bypass of healthcare facilities were younger age (OR 0.67, CI 0.46 – 0.99, p = 0.046) and employment in the civil service (OR 0.49, CI 0.31-0.79, p = 0.003). Older age (1.66, CI 1.07-2.58, p = 0.024), attainment of tertiary level of education (OR 1.57, CI 1.02-2.44, p = 0.043), high socioeconomic status (OR 1.94, CI 1.24 -3.02, p = 0.003) and presence of multiple morbidities (OR 1.66, CI 0.99-2.78, p = 0.053) were predictors of personal choice of health facility. Physical infrastructure was poor in all the facilities; most of the facilities depended on more than one source of power supply and water supply was mainly from other sources apart from pipe-borne. Identified predictors of satisfaction with care were age, occupation and seeking information about quality of care. Knowledge of the NHIS and patronage of faith-based health facilities were also predictors of satisfaction with care. Respondents who were younger than 35 years of age were more likely to be satisfied with care than those who were older (OR 1.85, CI = 1.05 – 3.25, p< 0.05). Private sector workers under the scheme (OR 1.84, CI 1.03 – 3.28, p< 0.05) were more likely to be satisfied with care than those employed in the civil service. Likewise, compared with those who did not seek information, those who did (OR 1.63, CI = 1.04 – 2. 53, p< 0.05) were more likely to report satisfaction with care. Respondents who claimed not to have a knowledge of the NHIS were more likely to be satisfied with care (OR 1.65, CI = 1.06 – 2.55, p< 0.05). Likewise, patronage of faith–based facilities was identified to be a predictor of satisfaction with care (OR 1.84, CI = 1.09 – 3.08, p< 0.05). Qualitative data revealed that there was a very low level of trust among the stakeholders. The design and operations of the scheme indicated that the NHIS managers lacked the technical and managerial skills required to manage the scheme and other stakeholders. Both the NHIS officials and the health care providers were of the opinion that the HMOs had more political influence than other stakeholders in the scheme, and were using this to take advantage of others. Enrolees and health care providers were reluctant to collaborate with the scheme at inception, because of the low level of trust in government policies generally. In addition, at inception of the scheme, the majority of the enrolees were arbitrarily allocated to the few available health care providers. For some of the enrolees, choice of health care facilities was based on perceived quality of care and occasionally, as a result of proximity to places of residence. Instances of corrupt and unethical practices were reported across the board among the scheme stakeholders. Discussion There was a high level of facility bypassing among study respondents, though only a few of them claimed to be aware of this. This finding is because of the allocation or assignment of majority of the enrolees to the few facilities that were available to participants in the scheme at its inception. The study also revealed that younger age enrolees and civil servants bypassed more than their respective counterparts did. Studies have shown that younger people are more likely to explore and become more adventurous than older individuals. The apparent bypassing among civil servants was largely because of the arbitrary allocation of reluctant enrolees to the available few health care providers at the inception of the scheme. This also explained the skewed distribution of the enrolees in these few facilities under the scheme. Findings also support the observation that most of the facilities with fewer enrolees were those that stayed away from the scheme at inception. However, the observed lopsided/uneven pattern was difficult to reverse despite the complaints of the facilities with fewer enrolees and the efforts of the scheme to address the skewness. It should also be noted that high social economic class is a strong factor of personal choice of healthcare facilities. The only plausible explanation was the fact that this group of enrolees were not civil servants and who had the financial capacity to pay the premiums, which enabled them buy into the scheme voluntarily and personally chose facilities where to receive care. The state of physical infrastructure in all the facilities that were involved in the study is illustrative of the weak health system in Nigeria. Poor facility infrastructure is a known recipe for the failure of social health insurance. Ability to search for healthcare facilities and in the process, the phenomenon of bypass as seen in this study appeared to play a major role in satisfaction with care amongst younger people, and among those from the private sector, the economic ability to search for and receive care in healthcare facilities of choice, and that meets their expectations. Similarly, enrolees who had the opportunity and sought information about the quality of care in the facilities before enrolment were more likely to be satisfied with care than those who did not seek information. Enrolees who claimed they had no knowledge of the scheme were more likely to be satisfied than those who had knowledge of it and may have had a higher expectation of the quality of care than they received. Satisfaction with care that was attributed to patronage of faith-based facilities in this study has similarities with findings in previous studies. Compared with other types of facilities, it has been reported that the likelihood of higher levels of satisfaction with care among those who patronise faith-based facilities, may have been as a result of higher levels of functional quality, (including spiritual care, that is more valued in this setting) in addition to the technical quality of care. The fundamental finding from the qualitative component of the study was a high level of mistrust of government by almost all the stakeholders involved in the scheme. This manifested itself in the reluctance of the majority of the private health facilities to collaborate with the government in providing health care services to enrolees on the scheme at inception. The same explanation goes for the then potential enrolees' outright refusal to take up the opportunity to access health care services through the scheme. Previous failed government policies both in the health and in the non-health sectors were cited as reasons for the low interest in the scheme. Because of this, except for the government health facilities that were instructed to do so, majority of the private facilities stayed away from providing care to enrolees on the scheme until some years later. Thus, the majority of these enrolees at inception were assigned to the few health facilities that were available. This is what was primarily responsible for the lopsided/uneven distribution of enrolees across the NHIS accredited facilities, whereby some had a high volume of enrolees, while the majority, especially those that showed interest in the scheme much later had very low volumes. Unfortunately, this pattern of enrolees' distribution may be irreversible. In addition, mistrust also exists between the NHIS and the HMOs, between the HMOs and providers, and to some extent between the enrolees and providers. It is important to note that the design of the scheme put the HMOs in a powerful position, which they used to influence the political class to their advantage. To compound the situation, NHIS officials had poor technical and managerial skills to administer the scheme. These are indications of an inefficiently managed health intervention. Under these circumstances, it is highly unlikely that universal health coverage could be achieved unless the observed challenges are appropriately addressed. In addressing these issues, a reform should be considered in the design of the scheme and appropriate training given to the NHIS officials saddled with its day-to-day operation. Conclusion This study has elucidated the reasons for the poor uptake and skewed distribution of enrolees across accredited NHIS facilities in the study area. In addition to poor structure and inefficient management, the high level of mistrust among the stakeholders has played a major role in the lopsided/uneven geo-spatial pattern of enrolees' distribution across the NHIS accredited health facilities. As it is presently structured and managed, the NHIS is highly unlikely to achieve its set objectives. It is advocated that a reform that addresses the observed anomalies be instituted to enable the scheme achieve its goals. This is a lesson for other countries planning to design and implement similar schemes.
In contemporary economics companies operate in a fast changing environment which forces them to adapt constantly. The never ending development seems to constitute the necessary condition for achieving the ultimate purpose of a company's function - the maximization of shareholder wealth. Company value is the greatest overall measurement of its efficient functioning. Thus numerous approaches to value were created. For public companies the market value of equity changes constantly and is publicly available. Companies actively support the increase in the market value of equity by releasing positive news. In this context the role of innovation announcements is crucial for all companies. Issues concerning innovation are strongly embedded in the current worldwide scientific discussion. However different sectors are unequally represented. The discussion on innovation in low-tech industries and services has received relatively little scholarly attention. Tourism represents both categories. The investigation of innovation in tourism is especially essential for the economy of the European Union as the sector contributes significantly to GDP generation, employment and investment. Increasing the knowledge of innovation in tourism is of vital theoretical and practical importance. Thus it was addressed in the present book. The research problem in the present book was expressed in the following question: what is the relationship between innovation announcements and the market value of equity of tourism enterprises? The main objective of the research was to measure the short- and long-term impact of innovation announcements on the market value of equity of tourism enterprises. Research aimed also at creating and verifying empirically the model explaining the relationship between innovation and the market value of tourism enterprises. The research contributed to the knowledge on innovation in tourism in two ways. First, the author's model representing the relationship was created. Second, the empirical research allowed the measurement of the effects of innovation announcements and the verification of the significance of the predictors of the market value of equity. In this research a systematic model-building procedure was applied. It relied on summarizing the existing scientific evidence on the relationship studied in order to build a comprehensive framework whilst also adding the author's propositions of predictors in the next step. In order to build the exhaustive design the method of systematic literature studies SALSA was employed. The study covered the period between 2000 and 2015. It used five scientific databases. The precise four-step procedure including content analysis and meta-synthesis resulted in the indication of two innovation-level, two firm-level innovation-related and five control variables important in the context of the relationship studied. Seven theoretically related predictors proposed by the author complemented this sound conceptual framework. In total the model accounted for eleven predictors: patent, CSR, type, degree of novelty involved, source, stage and the communication of innovation, R&D intensity and the innovativeness of the implementing company, squared R&D intensity and the interaction between R&D intensity and innovativeness. It covered also 8 control variables: industry, size, volume, total cash dividend, operational experience, leverage, return on equity and growth. The empirical research covered all the tourism enterprises listed on the main markets of the most important stock exchanges in the European Union in the period between February 2011 and February 2016. There were 111 such companies. The abnormal changes in the market value of equity resulting from innovation announcements of tourism enterprises constituted the subjects of analysis. Content analysis of the 9,000 innovation announcements resulted in creating the sampling frame of 985 releases referring to innovation consistent with the definition adopted in the present research. The research was performed on the representative sample of 398 observations. As Berk et al. state the total market value of a firm's equity equals the number of its shares times their current market price [2014]. If the number of shares is constant the change in their price becomes the right proxy for the changes in MV [Damodaran 2012]. In the present study the abnormal change in the market value of equity constituted the dependent variable. In line with the above considerations and previous research it was operationalized as the abnormal return. It was calculated in the short and the long term. In the short term the event-study method was employed. In the long term the buy-and-hold abnormal returns method was used. The expected returns in the short-term study were computed using the Carhart four-factor model [1997]. The abnormal returns were cumulated over the event windows and standardised which led to more powerful tests. The statistical significance of the changes in the market value of equity was tested using the Z-test and the two groups difference of means test. In order to test the author's model response surface regression and hierarchical regression were employed. The first one relies on introducing higher-order and interaction effects. The second one allows the testing of scientific hypotheses on the significance of particular predictors by building successive regression models, each adding new variables. The statistical analysis of the changes in the market value has hardly been reported in previous research. Such a study was performed here. It included the methods of descriptive statistics: central tendency, dispersion, skewness and peakedness. The first result of the empirical research reported in the book is the indication of the positive relationship between innovation announcements and the market value of equity of tourism enterprises. In the short term the effect concentrated in the event windows directly surrounding the event. In the +/- 1 day event window, the statistically significant increase in market value of equity was 0,38%. In the 6-months period it was 3,94%. The outcomes demonstrated that the initial reaction to the innovation news was adjusted in time. In the short term the market tended to undervalue the announced innovation. The difference in short- and long-term changes in the market value of equity and the statistical significance of the second suggested that the investors did not incorporate the new information immediately and fully. It means that the assessment of the effects of innovation announcements on the market value of equity of tourism enterprises should be considered over a longer period. The research did not deliver supportive evidence for the existence of leakage and dissemination effect. The significant changes in MV occurred in the period following the announcement. The fluctuations of market value of equity in the two days directly preceding the release and in the -6/-1 day event window were statistically insignificant. There is a small risk of significant fluctuations resulting from investors' aggressive trading prior to the announcement and unwinding part of the acquired position after it. The positive effects of successful innovation announcements were greater in number and magnitude than the negative effects of unsuccessful ones. The difference was statistically significant. In the +/- 1 day event window a typical change in market value of equity fell between 1,92% and -1,5%. In the half-year period the typical area of variability ranged between 16,07% and -8,95%. The distribution of changes in the market value of equity was right-skewed. It indicated that it was more probable to experience a high positive change in the market value of equity than to experience high loss. The leptokurtic character of the distribution showed that more variance resulted from infrequent extreme abnormal returns. The heterogeneity of the changes in the market value of equity required further explanation. In order to study the relationship between innovation announcements and the market value of equity of tourism enterprises the author's model was tested. The statistical significance of the groups of predictors and of the single predictors was verified. The outcomes of the analysis performed with the use of hierarchical regression indicated that innovation-level variables predict the changes in the market value of equity above and beyond the effect of the control and innovation-related company-level variables. The company-level innovation-related variables increased significantly the model's predictive power in the short term. In line with the initial hypothesis the research demonstrated that the effect of product innovation on the changes in market value resulting from innovation announcements was greater than that of other innovation types. New products may directly increase sales and impact positively on the company's cash flow. Furthermore it pointed out the positive effect of the first innovation announcement in relation to second and further releases. The informative value of the announcements beyond the first one was relatively small and caused little market reaction. In the context of market reactions the delivering of new information is essential. Moreover it was ascertained that in the short term the market rewarded the high advancement of the announced innovation and the high R&D intensity of the announcing company. In the case of hardly innovative tourism enterprises the market responded slightly to the development news and waited for the proof in the form of the innovation introduction. The high level of R&D intensity allowed tourism companies to differentiate themselves and increase innovative capabilities which was positively perceived by investors. In the long term investors acknowledged the positive effects of developing innovation in collaborative structures as it allows companies to benefit from the experience of collaborators and diminishes the risk. Furthermore the research delivered some inconclusive indications typified by the statistically insignificant results. The market positively received patented innovation in comparison to the non-patented one but the effect of such protection was relatively small. Patents are especially important for highly advanced technological innovation which is rare in tourism. Besides investors seemed optimistic about the innovation's degree of novelty involved. In line with the hypothesis they rewarded radical innovation as it carries higher potential benefits but the result was statistically insignificant. In the case of tourism dominated by minor upgrades investors treated radical innovation carefully and followed the "high risk – high return" strategy to a small extent. In line with the prediction in the long term the market seemed to reward highly R&D intensive tourism companies but the result was statistically insignificant. Moreover the research did not deliver supportive evidence for the existence of the second-order effect of R&D intensity and the interaction between R&D intensity and innovativeness. The inclusion of such variables did not predict changes in the market value of equity above and beyond the effect of the control variables. In the long term the diminishing marginal returns to R&D intensity were suggested but the effect was statistically insignificant. It may result from the level of expenditure on R&D in tourism which is too low to strongly advocate the diminishing marginal returns. In addition to the above outcomes the research delivered some unexpected results. It seemed that innovation without the elements of CSR was perceived better than innovation carrying such elements. The results were statistically insignificant. First, the CSR elements may have been perceived as superficial. Second, some previous research suggested that in non-innovative companies the concentration on social responsibility instead of enhancing innovativeness leads to a decrease in consumer satisfaction and in turn in market value [Luo and Bhattacharya 2006]. It seems to be the case in tourism. The number of innovation announcements released within a year before the event day did not have any impact on the reaction to the current announcement. Investors did not perceive companies reporting numerous innovations better. In the case of tourism enterprises it may result from the relatively high number of minor upgrades. It seems that their implementation did not guarantee the perception of the company as innovative. Each innovation announcement was evaluated irrespectively of such defined innovativeness. The results were statistically insignificant. The research did not deliver the supportive evidence for the market to reward the reported high advancement of innovation in the long term. The results were inconclusive due to their statistical insignificance. The research indicated that in the long term the stage of innovation at the moment of release was less important than in the short term. One possible explanation is that the period of six months following the development release might cover also the actual implementation. In the short term the effect of innovation developed in-house on the changes in market value resulting from innovation announcements was minimally greater than that of innovation from other sources. The calculated parameter and thus the actual difference were small. In the long term investors did not appreciate tourism companies' own efforts. The research question was positively answered by indicating the positive impact of innovation announcements on the market value of equity of tourism enterprises. Based on the empirical study all the hypotheses were verified. The study was burdened with several limitations. The research relied on specialist databases. As far as data accessibility is concerned the small amount of information inaccessible through databases required it to be collected directly from companies. Moreover the choice of linear regression modelling might not necessarily allow the capture of all possible effects. Besides which although the advantages of covering the period of relative stability have been discussed in the book the determination of the time frame prevents the generalisation of results in a period of major economic downturns. The research covered comprehensive announcements reporting innovation consistent with the definition adopted. As discussed in the book such an approach offered numerous benefits. However the omission of imprecise, incomplete and partial releases may be considered a certain limitation as this kind of information may also stimulate market reaction to some extent. In the light of the results of the present research it seems that a promising direction for further research is the in-depth, qualitative analysis explaining why and how the predictors influenced the market value of equity. It should cover the reasons behind the statistical significance of the predictors demonstrated in this research. Also the growing potential of alternative trading systems suggests the need for the replication of the study in this context. It is especially important for tourism enterprises which are mainly relatively small. Furthermore it seems important to compare the effects of innovation on tourism companies with the effects on other low-tech companies. It could deliver insights into the discussion on the specificity of tourism companies. In the light of the results obtained in this study it seems necessary to deepen the research on the interaction between innovation and corporate social responsibility. The qualitative analysis of the possible synergic effects appears to be a valuable course for further investigation. Value is the most comprehensive measure of company activity. However it is not the only one especially since companies in different periods may pursue different strategies (e.g. profit maximization). The effects of innovation on different financial measures seem to be an important direction for further research. The research contributed to the current scientific discussion on innovation in services with special regard to innovation in tourism. It complemented the broader knowledge on the efficiency of capital markets by providing a conceptual overview and empirical evidence. The research introduced the author's model representing the relationship between innovation announcements and the market value of equity of tourism enterprises. Thus it added to the understanding of the predictors of the market value of equity. The research was based on a representative sample and provided firm support for previous research indicating the positive effects of innovation on tourism companies. ; National Science Centre, Poland
