The Collective Clemency Bill passed by the Italian Parliament in July 2006 represents a natural experiment to analyze the behavioral response of individuals to an exogenous manipulation of prison sentences. On the basis of a unique data set on the postrelease behavior of former inmates, we find that 1 month less time served in prison commuted into 1 month more in expected sentence for future crimes reduces the probability of recidivism by 0.16 percentage points. From this result we estimate an elasticity of average recidivism with respect to the expected punishment equal to - 0.74 for a 7-month period. (c) 2009 by The University of Chicago. All rights reserved..

Laws express rules of conduct ('obligations') enforced by the means of penalties and rewards ('incentives'). The role of incentives in shaping individual behaviour has been largely analysed in the traditional economic literature. On the contrary, very little is known about the specific role of obligations. In this paper we test whether or not obligations have any independent effect on cooperation in a public good game. The results show that, for given marginal incentives, different levels of minimum contribution required by obligation determine significantly different levels of average contributions. Moreover, obligations per se cannot sustain cooperation over time, even if they affect the rate of decline of average contributions. Finally, unexpected changes in the minimum contribution have asymmetric dynamic effects on the levels of cooperation: a reduction does not alter the descending trend of cooperation, whereas an increase induces a temporary re-start in average contributions.JEL classification: C91; C92; H26; H41; K40

The authors examine the impact of prison conditions on future criminal behavior. The take over is based on a unique dataset on the post-release behavior of about twenty thousand Italian former prison inmates. The authors use variation in prison assignment as a means of identifying the effects of prison overcrowding, deaths in prison, and degree of isolation on the probability of reoffending. They do not find compellingevidence of (specific) deterrent effects of experienced prison severity. The measures of prison severity do not reduce the probability of recidivism. Instead, all point estimates suggest that harsh prison conditions increase post-release criminal activity, though they are not always precisely estimated.