Idiosyncratic risk, aggregate risk, and the welfare effects of social security

We ask whether a pay-as-you-go financed social security system is welfare improving in an economy with idiosyncratic productivity and aggregate business cycle risk. We show analytically that the whole welfare benefit from joint insurance against both risks is greater than the sum of benefits from insurance against the isolated risk components. One reason is the convexity of the welfare gain in total risk. The other reason is a direct risk interaction which amplifies the utility losses from consumption risk. We proceed with a quantitative evaluation of social security’s welfare effects. We find that introducing an unconditional minimum pension leads to substantial welfare gains in expectation, even net of the welfare losses from crowding out. About 60% of the welfare gains would be missing when simply summing up the isolated benefits

The Japanese saving rate between 1960 and 2000: productivity, policy changes, and demographics

Saving rate, Japan, Overlapping generations, Calibration, E21, E32,

Multidimensional Spline Interpolation: Theory and Applications

Interpolation, Multidimensional cubic splines, C63, C65,

On the Welfare Effects of Eliminating Business Cycles

We investigate the welfare effects of eliminating business cycles in a model with substantial consumer heterogeneity. The heterogeneity arises from uninsurable and idiosyncratic uncertainty in preferences and employment, where regarding employment, we distinguish among employment and short- and long-term unemployment. We calibrate the model to match the distribution of wealth in U.S. data and features of transitions between employment and unemployment. Unlike previous studies, we study how business cycles affect different groups of consumers. We conclude that the cost of cycles is small for almost all groups and, indeed, is negative for some. (Copyright: Elsevier)

Revisiting the Welfare Effects of Eliminating Business Cycles

We investigate the welfare effects of eliminating business cycles in a model with substantial consumer heterogeneity. The heterogeneity arises from uninsurable and idiosyncratic uncertainty in preferences and employment status. We calibrate the model to match the distribution of wealth in U.S. data and features of transitions between employment and unemployment. In comparison with much of the literature, we find rather large effects. For our benchmark model, we find welfare effects that, on average across all consumers, are of a bit more than one order of magnitude larger than those computed by Lucas (1987). When we distinguish long- from short-term unemployment, long-term unemployment being distinguished by poor (and highly procylical) employment prospects and low unemployment compensation, the average gain from eliminating cycles is as much as 1% in consumption equivalents. In addition, in both models, there are large differences across groups: very poor consumers gain a lot when cycles are removed (the long-term unemployed as much as around 30%), as do very rich consumers, whereas the majority of consumers---the "middle class"---sees much smaller gains from removing cycles. Inequality also rises substantially upon removing cycles. (Copyright: Elsevier)Cost of business cycles; Incomplete markets; Heterogeneity