Three Essays in Economics: Group Identity and Punishment, Human Capital Development, and Moral Hazard




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This dissertation focuses on individual decision making with the presence of social interaction. In the first chapter, we design a lab experiment to investigate how group identity influences cooperation and peer punishment under the voluntary contribution mechanism of public goods. We find that monetary punishment leads to an increase in the public goods contributions, and the impact is greater in the treatments with groups than in the baseline without groups. In addition, participants punish ingroup under-contributors more severely. However, these effects are significant only when all the participants are made aware that the punishers’ group identities are to be revealed to the punishees. In the second chapter, we conduct a field experiment in a large Chinese garment factory to investigate the impact of social distance on professional training efficiency. Our results show that closer social distance stimulates voluntary technology transfer from trainers to trainees. Furthermore, with one more technique transferred, an average trainee can produce more in the exit test of the training, showing that closer social distance between trainers and trainees promotes training efficiency. In the third chapter, we try to estimate the moral hazard effect of having health insurance on medical service spending, and the heterogeneity in it. We develop a theoretical model to illustrate the heterogeneity in the moral hazard effect, and then test it using the data from the Oregon Health Insurance Experiment. We find that the moral hazard effects of having health insurance are significantly greater for individuals who are 35 to 55 years of age, compared to individuals who are 20 to 35 years of age. They are also greater than individuals who are 55 to 64, but statistically insignificant. Moreover, we find that the moral hazard effects on outpatient visits decrease as individuals’ family income increases. Our results thus indicate that a universal cost-sharing plan in health insurance policies may not be efficient.



Group identity, Occupational training, Moral hazard, Punishment (Psychology), Cooperation, Public goods, Social distance, Technology transfer, Health insurance


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