Gravitational Smearing of Minimal Supersymmetric Unification Predictions

A short and mean paper.Comment: 10 pages total + 1 postscript figure (included), revised: all lines are TRULY < 70 characters long (try it!); LBL-32905, UCB-PTH-92/3

The Role of Expectations in the Provision of Public Goods Under the Influence of Social Identity

Individuals who share a common identity show persistently elevated contributions to public goods. Yet, so far the factors that actually trigger this welfare enhancement are not precisely understood. We investigate two channels: (1) subjects' expectations on group members' cooperativeness and (2) the degree to which they reciprocate these expectations by own contributions' i.e. their conditional cooperation. To this purpose we induce identity in the lab and implement an in-group, out-group and partner matching protocol in a ten-period public good game. Our results yield that comparatively higher expectations on in-group than on outgroup members' cooperativeness are the main driver for welfare enhancements in identity homogeneous groups. The degree of conditional cooperation is, however, similar in all matching protocols. Merely individuals initially identified as free-riders seem to reciprocate a limited range of expectations by higher own contributions when matched with in-group than with out-group members. Nevertheless, our findings clearly underline the paramount importance of expectations in determining cooperation under social identity

Negative Reciprocity and its Relation to Anger-Like Emotions in Homogeneous and Heterogeneous Groups

Several studies have shown that social identity fosters the provision of public goods and enhances the willingness to reciprocate cooperative behavior of group members dependent on the social environment. Yet, the question of how social identity affects negative reciprocity in identityhomogeneous and -heterogeneous groups has received only little attention. Consequently, we seek to fill this gap by examining whether social identity affects individuals' willingness to sanction deviating group members in a public good context. Moreover, we devote particular attention to the role of anger-like emotions in negative reciprocity. To test our hypotheses we employ one-shot public good games in strategy method with induced social identity. Our results indicate that members of identity homogeneous groups punish much less often and in smaller amounts than of identity heterogeneous groups when they face contributions smaller than their own. We also find that anger-like emotions influence punishment behavior much stronger when individuals are matched with members of different identities than in identity homogenous groups. These findings contribute to the better understanding of the nature of social identity and its impact on reciprocity, improving economists ability to predict behavior taking emotions also into consideration

Cooperation Preferences in the Provision of Public Goods: An Experimental Study on the Effects of Social Identity

Traditionally economic theory assumes that preferences are stable facilitating positive predictions of economic policy. While there is conflicting experimental evidence on the temporal stability of cooperation preferences in public goods provision, surprisingly little is known about their stability in different institutional settings. We contribute to this literature by testing whether social identity impacts on cooperation preferences in public goods provision. Specifically, our experiment features a within subject design based on one shot public good games in strategy method, which are carried out in random, in and out group matching protocols. Our findings indicate that cooperation preferences are not stable across these matching circumstances. Quite to the contrary, we find that when matched with in group members, subjects consistently show the preference for higher levels of conditional cooperation and thus less self serving bias than in out group matching. Additionally, while the probability to be a conditional cooperator remains stable under each treatment, we identify an elevated propensity to be a free rider when matched with individuals of a different identity. These results indicate that it can be reasonable to devise policy institutions that strengthen the feeling of belonging to a particular group in order to enhance social welfare