Markovian Social Security in Unequal Societies

In this paper, we develop a dynamic political-economic theory of social security. We analytically characterize a Markov perfect equilibrium and find that the interaction between Markovian tax policy and tax distortion on private investment in human capital shapes an intertemporal policy rule, linking taxes positively over time. By allowing current taxpayers to influence their own future social security benefits, the positive intertemporal tax linkage provides political support for social security. Moreover, this positive tax linkage leads to a negative correlation between wage inequality and the size of a nation's social security system, consistent with the empirical pattern observed across OECD countries.