Suchergebnisse

This article reports the results of an experiment to determine if increased enforcement of sanitation laws improves the cleanliness of city streets. The experiment was conducted over a six-week period in New York City Increasing the number of sanitation policemen was found to decrease the rate of production of litter as measured by daily cleanliness ratings. Implications for future research and public policy are discussed.

AbstractA person's egonet, the set of others with whom that person is connected, is a personal sample of society which especially influences that person's experience and perceptions of society. We show that egonets systematically misrepresent the general population because each person is included in as many egonets as that person has "friends." Previous research has recognized that this unequal weighting in egonets leads many people to find that their friends have more friends than they themselves have. This paper builds upon that research to show that people's egonets provide them with systematically biased samples of the population more generally. We discuss how this ubiquitous egonet bias may have far reaching implications for people's experiences and perceptions of frequencies of other people's ties and traits in ways that may influence their own feelings and behaviors. In particular, these egonet biases may help explain people's tendencies to disproportionately experience and overestimate the prevalence of certain types of deviance and other social behaviors and consequently be influenced toward them. We illustrate egonet bias with analyses of all friends among 63,731 Facebook users. We call for further empirical investigation of egonet biases and their consequences for individuals and society.

AbstractFor marriage promotion interventions to be effective, social policy for increasing other social benefits (e.g., child welfare, family financial self‐sufficiency), they must increase numbers and/or quality of marriages in such a way to produce those other social benefits. Evidence should show that particular interventions (a) produce increases in numbers and/or quality of marriages, (b) produce increases in other benefits, and (c) produce increases in other benefits through the changes in marriages described in (a). There is some evidence that marriage promotion interventions have produced small increases in numbers and quality of marriages, but there is little evidence regarding the extent to which these interventions have produced other intended social benefits. We describe the nature of additional data and analyses that would enable us to determine the extent to which marriage promotion interventions are effective ways to increase other social benefits.

The Laakso-Taagepera index (Laakso and Taagepera, 1979) has become the most commonly used measure to specify the 'effective'number of political parties in a party system where parties vary substantially in their vote and/or seat shares. It is well known that the Laakso-Taagepera index is the inverse of the even more widely used Herfindahl-Hirschman index of concentration (Hirschman, 1945; Herfindahl, 1950; cf. Taagepera and Grofman, 1981). Drawing on little known work by Feld and Grofman (1977, 1980) on the so called 'class-size paradox', it can also be shown that both indices may be re-expressed as simple functions of a distribution's mean and variance. As far as we can judge, these latter relationships appear to be unknown in the party and electoral systems literatures. By expressing the Herfindahl-Hirschman index and the Laakso-Taagepera index in terms of means and variances we can see that each index has a 'natural' interpretation in terms of well known statistical parameters which allows their fundamental mathematical properties to be more clearly revealed.

The Laakso-Taagepera index (Laakso & Taagepera, 1979) has become the most commonly used measure to specify the 'effective' number of political parties in a party system where parties vary substantially in their vote &/or seat shares. It is well known that the Laakso-Taagepera index is the inverse of the even more widely used Herfindahl-Hirschman index of concentration (Hirschman, 1945; Herfindahl, 1950; cf. Taagepera & Grofman, 1981). Drawing on little known work by Feld & Grofman (1977, 1980) on the so called 'class-size paradox', it can also be shown that both indices may be re-expressed as simple functions of a distribution's mean & variance. As far as we can judge, these latter relationships appear to be unknown in the party & electoral systems literatures. By expressing the Herfindahl-Hirschman index & the Laakso-Taagepera index in terms of means & variances we can see that each index has a 'natural' interpretation in terms of well known statistical parameters which allows their fundamental mathematical properties to be more clearly revealed. References. [Reprinted by permission of Sage Publications Ltd., copyright 2007.]