Partner Selection into Policy Relevant Field Experiments

This study investigates the issue of self-selection of stakeholders into participation and collaboration in policy-relevant experiments. We document and test the implications of self-selection in the context of randomised policy experiment we conducted in primary schools in the UK. The main questions we ask are (1) is there evidence of selection on key observable characteristics likely to matter for the outcome of interest and (2) does selection matter for the estimates of treatment eff ects. The experimental work consists in testing the e ffects of an intervention aimed at encouraging children to make more healthy choices at lunch. We recruited schools through local authorities and randomised schools across two incentive treatments and a control group. We document the selection taking place both at the level of local authorities and at the school level. Overall we nd mild evidence of selection on key observables such as obesity levels and socio-economic characteristics. We find evidence of selection along indicators of involvement in healthy lifestyle programmes at the school level, but the magnitude is small. Moreover, We do not find signifi cant di erences in the treatment e ffects of the experiment between variables which, albeit to a mild degree, are correlated with selection into the experiment. To our knowledge, this is the rst study providing direct evidence on the magnitude of self-selection in fi eld experiments.

Personal indebtedness, community characteristics and theft crimes

Becker (1968) and Stigler (1970) provide the germinal works for an economic analysis of crime, and their approach has been utilised to consider the response of crime rates to a range of economic, criminal and socioeconomic factors. Until recently however this did not extend to a consideration of the role of personal indebtedness in explaining the observed pattern of crime. This paper uses the Becker (1968) and Stigler (1970) framework, and extends to a fuller consideration of the relationship between economic hardship and theft crimes in an urban setting. The increase in personal debt in the past decade has been significant, which combined with the recent global recession, has led to a spike in personal insolvencies. In the context of the recent recession it is important to understand how increases in personal indebtedness may spillover into increases in social problems like crime. This paper uses data available at the neighbourhood level for London, UK on county court judgments (CCJ's) granted against residents in that neighbourhood, this is our measure of personal indebtedness, and examines the relationship between a range of community characteristics (economic, socio-economic, etc), including the number of CCJ's granted against residents, and the observed pattern of theft crimes for three successive years using spatial econometric methods. Our results confirm that theft crimes in London follow a spatial process, that personal indebtedness is positively associated with theft crimes in London, and that the covariates we have chosen are important in explaining the spatial variation in theft crimes. We identify a number of interesting results, for instance that there is variation in the impact of covariates across crime types, and that the covariates which are important in explaining the pattern of each crime type are largely stable across the three periods considered in this analysis.