I evaluate the welfare effects of exogenous changes in immigration policy by constructing a heterogeneous agent overlapping generations model with agents differing in age, origin, and skills. Calibrating the model to Germany, I match the main features of the social security and tax systems, and account for differences in inter-generational transmission of skills and fertility between immigrants...

This paper provides a review of the economic literature on social security systems and of practical experiences with building social security institutions. The focus is on the design of the institutions, and on the complicated relation between social security, economic welfare and economic growth at the macro-level. The aim of this review is to provide lessons for building social security schem...

This paper investigates how competitive cyber-insurers affect network security and welfare of the networked society. In our model, a user’s probability to incur damage (from being attacked) depends on both his security and the network security, with the latter taken by individual users as given. First, we consider cyberinsurers who cannot observe (and thus, affect) individual user security. Thi...

This paper explores the general-equilibrium impact of social security portfolio diversiŽ cation into private securities, either through the trust fund or private accounts. The analysis depends critically on heterogeneities in saving, production, assets, and taxes. Limited diversiŽcation weakly increases interest rates, reduces the expected return on short-term investment (and the equity premium...

This paper studies optimal pay-as-you-go social security with positive bequests and endogenous fertility. With an investment externality, a competitive solution without social security suffers from under-investment in capital and over-reproduction of population. We show that social security can improve welfare by reducing fertility and increasing capital intensity. We also illustrate numericall...

The Transition from Welfare to Work and the Role of Potential Labor Income It is often argued that the high level of welfare claims in Germany causes little incentive for workers with low productivity to seek for a job. We examine the influence of the ratio between estimated potential labor income and the welfare payment level on the probability of leaving social welfare. Using the GSOEP, we es...

This paper studies the design of a nonlinear social security scheme in a society where individuals differ in two respects: productivity and degree of myopia. Myopic individuals may not save “enough” for their retirement because their “myopic self” emerges when labor supply and savings decisions are made. The social welfare function is paternalistic: the rate of time preference of the far-sighte...

Social welfare is one of the accepted goals of the United States and of the entire free world. Great interest attaches, therefore, both in this country and elsewhere, to the status of social wegare programs in the United States today. The standard of living and general welfare of the American people derive from the multiform activities of a free people, working individually, through voluntary g...

Yamada, Tomoaki—A politically feasible social security reform with a two-tier structure This paper investigates the welfare implications and political feasibility of social security reforms with a two-tier structure in Japan. We evaluate social security reforms from two points of view: (i) the ex-ante expected value of future generations, and (ii) whether current generations prefer reform to th...