Numerous studies have shown that public service motivation (PSM) is higher among public sector employees, particularly in western countries. But whether these trends result from high-PSM individuals selecting into public sector employment or from on-the-job socialization remains subject to debate. We address this question utilizing novel panel data on Russian university students. Examining the relationships between PSM and sectoral employment both before and after students enter the labor force, we find that: (1) high-PSM students are more likely to prefer public sector employment; (2) high-PSM students are more likely to be employed in the public sector following graduation; and (3) PSM increases upon entry into the workplace at approximately the same rate in both the public and private sectors. These findings suggest that at least during early career stages, the association between PSM and public sector employment results largely from an attraction-selection process, rather than a socialization process. Our analyses additionally provide evidence that theories of PSM based on the western experience may generalize to the context of developing or post-communist countries, despite the prevalence of corruption and a less pronounced public service ethos in many of these countries.