Reconsidering Causes and Effects of Public Service Motivation: Old Questions, New Evidence from a Sample of Twins

Abstract

I leverage an identical co-twin control design to assess whether education, political ideology, and spirituality are antecedents of public service motivation and whether hours spent volunteering and a preference for public sector employment are outcomes of public service motivation. I show that, after differencing out unobserved genetic and social endowments, self-sacrifice is decreasing in political conservatism and increasing in spirituality; that commitment to the public interest is increasing in spirituality; that attraction to public policymaking is decreasing in education; and that compassion is decreasing in political conservatism and increasing in spirituality. Commitment to the public interest and attraction to public policymaking predict a stated preference for public sector employment compared to nonprofit and private sector employment, while self-sacrifice and compassion do not. None of the dimensions of public service motivation appear to predict the number of hours spent volunteering. Although low statistical power and measurement error may explain some of the null findings, the results are credibly causal and have a number of implications for a theory of public service motivation, empirical research on the construct, and its potential use in practice.