The paper discusses the consequences for the functioning of different pension systems of various types of socioeconomic changes, mainly demographic developments, variations in productivity growth and changes in real interest rates. Two of the pension systems have exogenous and four have...

With fixed costs of participating in the stock market, consumers with high income will participate in the stock market, but consumers with lower income will not participate. If a fully-funded defined-contribution social security system tries to exploit the equity premium by selling a dollar of...

This paper describes how three money's worth measures the benefit-to-tax ratio, the internal rate of return, and the net present value are calculated and used in analyses of social security reforms, including systems with privately managed individual accounts invested in equities. Declining...

Does Social Security redistribute across cohorts? Or is it a program for purchasing the jobs' of the elderly? I formalize both models, showing how they have some predictions in common the most important of which is that generational accounts have the appearance of a pyramid scheme.' I also...

Based on explicit present value calculations, the paper criticizes the view that the PAYGO system wastes economic resources. In present value terms, there is nothing to be gained from a transition to funded system even though the latter offers a permanently higher rate of return. The sum of the...

This paper focuses on Social Security benefit claiming behavior, a take-up decision that has been ignored in the previous literature. Using financial calculations and simulations based on an expected utility maximization model, we show that delaying benefit claim for a period of time after...

166 countries have some kind of public old age pension. What economic forces create and sustain old age Social Security as a public program? We document some of the internationally and historically common features of Social Security programs including explicit and implicit taxes on labor supply,...

Why are the old politically successful? We build a simple interest group model in which political pressure is time-intensive, showing that in the political competitive equilibrium each group lobbies for government policies that lower their own value of time but that the old do so to a greater...

Social Security trust fund portfolio diversification to include some equities reduces the equity premium by raising the safe real interest rate. This requires changes in taxes. Under the hypothesis of constant marginal returns to risky investments, trust fund diversification lowers the price of...