6 directly related to the work of national government officials; a well-defined population of public and private sector subjects; and with evidence on the actual sector choices of pro-social individuals.

Using behavioral data, Buurman, et al. (2012) also find that public sector employees are more pro-social, but in the Netherlands and for public sector employees broadly rather than general government employees specifically. Gregg et al. (2011), using self-reported hours of overtime worked, examine the intrinsic motivation of non-profit workers, and not general government employees specifically. They conclude that only workers in the non-profit caring sector report significantly more unpaid overtime. Employees in the non-profit, non-caring sector report roughly the same levels of overtime as those in the for-profit sector. In contrast, we find significantly greater pro-social behavior in the “non-profit non-caring sector” (central government employees and students who are committed to entering the Ministry of Finance). One possible explanation for the different results is that we use a more precise measure of pro-social motivation. A more interesting explanation lies in possible differences in the labor market: to the extent that the Indonesia’s nonprofit caring sector is small compared to the United Kingdom’s, the non-profit, non-caring sector may attract more pro-social employees than it otherwise would.

Serra et al. (2011) also explore the mission orientation of public sector workers in a nonOECD setting. They use data on medical professionals, front-line providers rather than general government officials. They also conduct their study in Ethiopia, a country that ranks much lower than Indonesia in the pro-sociality of its public sector. Finally, they measure pro-sociality differently, using behavior in a trust game, and whether subjects say that the opportunity to help the poor is most important to them. In contrast to our findings, they find that government and private sector medical professionals in Ethiopia are similar along these two dimensions. Both of these groups score lower on the two dimensions than employees in non-profit, non-governmental organizations.

Our unique subject pool also allows us to advance understanding of the role of selection in the emergence of differences in pro-social motivations between government and private sector employees. This is a central issue in the literature. Selection is at work if organizations attract workers who share their mission orientation (Besley and Ghatak, 2005; Gregg et al. 2011; Serra et al. 2011). Intrinsically-motivated individuals always behave pro-socially; differences across organizations in the attitudes of their employees are therefore driven by the selection of intrinsicallymotivated individuals into organizations that share their mission.<sup>5</sup> However, a growing literature also suggests that individual norms evolve over time as a function of the other individuals with whom they are in contact – their families, but also the organizations in which they are active (Dohmen et al. 2012; Tabellini, 2008; Bisin and Verdier, 2001; Bulte and Horan, 2011). This literature implies that individuals in organizations with a pro-social mission become more pro-social over time.

Only Gregg, et al. (2011) have provided empirical evidence on the issue. They look at respondents from the non-profit caring sector, comparing those respondents who switch to the forprofit caring sector with respondents who do not switch. If selection is operating, those who switch should be less pro-social and report lower levels of unpaid overtime. This is what Gregg et al. (2011) find.<sup>6</sup> Our study design better allows us to exclude competing explanations for these

> 5 Francois (2000) makes a somewhat different selection argument:  individuals inclined to pro-social behavior should only exhibit it in non-profit or government settings where managers do not have high-powered incentives to take advantage of the free effort that they get from pro-social employees by reducing costs elsewhere in the organization.

> 6 The 83 respondents who reported moving from the non-profit to the for-profit caring sector were significantly less