19 in the Mexico field experiment, using questionnaire-based measures of ability and motivation, Dal Bo et al. (2013) predict and find no effect or a slightly positive effect of wages on motivation. Fourth, subjects in our treatment know their task-relevant ability exactly and can clearly identify their contribution to the public sector mission. They are therefore more likely to take into account their actual contribution to the pro-social mission in deciding whether to join the public sector (λ is higher).

Finally, the two settings capture different segments of the public sector. The subjects in their field experiment were attracted by government job advertisements seeking applicants who would take jobs in remote and underserved areas of Mexico. Such advertisements may therefore attract more highly motivated workers, regardless of the level of pay (indeed, pay levels were only revealed to subjects once they had already chosen to apply). In this case, as the earlier discussion of the model indicates, changes in public sector pay have a weaker effect on the observed motivation of new entrants. In contrast, all of our subjects are contemplating careers that would be fungible across the private and public sectors (accounting, auditing, economics, management) and where private sector earnings of those who choose the private sector will be at least as high as those who choose the public. The distribution of intrinsic motivation among these individuals is likely to be shifted to the left (downwards) relative to the Mexican sample, but at the same time similar to the distribution of motivation of potential entrants to a large class of public sector jobs.

# **_Pro-social behavior in the government and private sectors_**

Column 1 in Table 3 indicates that, on average, pooling high and low wage public sector pay regimes, those who choose to work in the public sector are significantly more pro-social than those who do not. It is not obvious that this same relationship should hold with real world public and private sector workers. The pro-sociality of real public sector workers is contingent on numerous factors and need not be higher than private sector workers. First, mission-matching is unlikely to be exact. On the one hand, workers’ public sector motivation may or may not correspond to their preferences over the specific missions of the Ministries of Finance, Health, or Public Works, and their preferences for those specific missions are typically difficult to assess. On the other hand, work in the public sector can also be attractive for other reasons, ranging from job security to the enjoyment of tasks in the public sector that are less common in the private sector. Public sector work is heterogeneous in the degree to which workers can assess their individual contributions to social welfare: front line workers can better observe their contribution to social welfare than others. Finally, the political economy of public sector activity shifts public sector goals away from prosociality more so in some countries than in others.

The “experimental” public sector avoids these ambiguities, since pro-sociality and the public sector mission are tightly controlled and the production function of public sector benefits seamlessly and transparently translates subject effort into benefits for society. The question, then, is whether, in the particular Indonesian context in which the laboratory experiments are conducted, real world public sector workers, who operate off of the front lines (in the Ministry of Finance), in a country where the public sector is not known to be among the most efficient or to be driven by a pro-social mission, also exhibit greater pro-sociality than private sector workers.

Our subject pool allows us to compare the pro-sociality of students largely destined for the private sector (the UI students) with those who have already agreed to join, but have not yet joined, the public sector, students attending Sekolah Tinggi Akuntansi Negara (STAN), the State College of Accountancy. Though many UI students express interest in working in the public sector, none have actually committed to entering the public sector and the vast majority of them will, in fact, take