Suchergebnisse

Post-mortems of the financial crisis typically mention "black swans" as the rare events that were the Achilles heel of financial models, manifesting themselves as "25 standard deviation events occurring several days in a row". Here, we briefly discuss the implications of "black swan" events in asset pricing and risk management. We then show that the "black swans" problem virtually disappears for S&P Index returns when surprises are measured relative to the standard deviation of the conditional S&P distribution. In our illustration, we use the one-day-lagged VIX as an easy-to-understand measure of that conditional S&P standard deviation.

Purpose. Given the need for comprehensive and multidisciplinary active living interventions, this article describes an innovative partnership for park design and evaluation. Design. The Trust for Public Land partnered with the RAND Corporation and the San Francisco Department of Public Health to generate context-sensitive active park design, establish evaluation methods, and build the framework for future collaboration. Setting. These partners worked together from 2009 to 2012 to design, renovate, and study parks in San Francisco, California. Subjects. The three partnering organizations are the focus of this article. Intervention. The Trust for Public Land's Parks for People–Bay Area Program raised more than $16 million to renovate three San Francisco parks, which served as the intervention for a study that initially brought the three partnering organizations together. Measures. The authors, who represent the three partners, collaborated to develop the lessons learned. Analysis. This article is a description and commentary about a partnership that emphasized community involvement and rigorous evaluation. Results. Lessons learned and elements for successful partnerships include collaborating with organizations with differing expertise, deciding upon goals initially, finding a common language, involving local communities, and recognizing the importance and appropriate role of evaluations. Conclusion. The model for collaboration and community involvement presented supports and encourages other organizations to use strategic, multidisciplinary partnerships and highlights the importance of evaluation.

Concerns about safety and perceived threats have been considered responsible for lower use of parks in high-poverty neighborhoods. To quantify the role of perceived threats on park use, we systematically observed 48 parks and surveyed park users and household residents in low-income neighborhoods in the City of Los Angeles. Across all parks, the majority of both park users and local residents perceived parks as safe or very safe. We noted apparently homeless individuals during nearly half of all observations, but very few instances of fighting, intimidating groups, smoking, and intoxication. The presence of homeless individuals was associated with higher numbers of park users while the presence of intoxicated persons was associated with lower numbers. Overall, the strongest predictors of increased park use were the presence of organized and supervised activities. Therefore, to increase park use, focusing resources on programming may be more fruitful than targeting perceived threats.

Purpose. To assess the use of new pocket parks in low-income neighborhoods. Design. The design of the study was a quasi-experimental post-test only comparison. Setting. Los Angeles, California, was the setting for the study. Subjects. Subjects were park users and residents living within .5 mile of three pocket parks and 15 neighborhood parks. Intervention. The creation of pocket parks. Measures. We used the System of Observing Play and Recreation in Communities (SOPARC) tool to measure park use and park-based physical activity, and then surveyed park users and residents about their park use. Analysis. We surveyed 392 and 432 household members within .5 mile of the three pocket parks before and after park construction, respectively, as well as 71 pocket park users, and compared them to 992 neighborhood park users and 342 residents living within .5 mile of other neighborhood parks. We compared pocket park use to playground area use in the larger neighborhood parks. We used descriptive statistics and generalized estimating equations for the analysis. Results. Overall, pocket park use compared favorably in promoting moderate-to-vigorous physical activity with that of existing playground space in nearby parks, and they were cost-effective at $0.73/MET hour (metabolic equivalent hour) gained. Pocket park visitors walked an average of .25 miles to get to a park. Conclusions. Pocket parks, when perceived as attractive and safe destinations, may increase physical activity by encouraging families with children to walk there. Additional strategies and programs may be needed to encourage more residents to use these parks.

"In September 2017, Puerto Rico was struck by two major hurricanes—Irma and Maria—that intensified existing challenges in Puerto Rico's health and social services infrastructure. In the aftermath, the government of Puerto Rico created a long-term recovery plan built on an evidence-based assessment of the damage from the hurricanes and the ongoing needs across Puerto Rico. Development of the recovery plan was supported by the Federal Emergency Management Agency, other federal agencies, local stakeholders, and analysis from the Homeland Security Operational Analysis Center (HSOAC), operated by RAND Corporation under contract with the U.S. Department of Homeland Security. HSOAC research provided the foundation for the 31 courses of action in the recovery plan addressing the health and social services sector. These actions are a mix of social, governmental, fiscal, and economic policies and reforms. This collection of actions presents an opportunity to build a more resilient health and social services infrastructure and regional health care networks to ensure reliable access to services, promote health and well-being, and more efficiently and effectively respond to public health crises and future disasters. The actions span the areas of health care, public health and emergency preparedness, environmental health, mental and behavioral health, and social services. The damage and needs assessment and courses of actions cover four major themes: building system capacity to respond both during disasters and routine times; strengthening the health and social services workforce; strengthening support services for at-need populations; and creating health-promoting communities.

Introduction -- Puerto Rico's Health and Social Services Sectors Before the Hurricanes -- Damage and Needs Assessment -- Themes for Recovery and Courses of Action -- Implementation Considerations -- Appendix A: Courses of Action -- Appendix B: Health and Social Services Sector COAs -- Appendix C: COAs from Other Sectors Included in the Health and Social Services Portfolio -- Appendix D: Health and Social Services Portfolios -- Appendix E: Plan Development.