Small assumptions (can) have a large bearing: evaluating pension system reforms with OLG models

The objective of this paper is to inquire the consequences of some simplifying assumptions typically made in the overlapping generations (OLG) models of pension systems and pension system reforms. This literature is largely driven by policy motivations. Consequently, the majority of the papers is extremely detailed in the dimension under scrutiny. On the other hand, complexity of general equilibrium OLG modeling necessitates some simplifications in the model. We run a series of experiments in which the same reform in the same economy is modeled with six different sets of assumptions concerning the shape of the utility function, time inconsistency, bequests? redistribution, labor supply decisions and internalizing the linkage between social security contributions and benefits in these decisions as well as public spending. We find that these assumptions significantly affect both the size and the sign of the macroeconomic and welfare measures of policy effects with the order of magnitude comparable to the reform itself.