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,...

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...

Social security system old age insurance systems are devices for the sharing of income risks of elderly people with others. Risks can be shared intergenerationally (with the young of the same country), intragenerationally (with other elderly of the same country), or internationally (with...

Recent theoretical and empirical studies have emphasized the fact that the prospect of international migration increases the expected returns to skills in poor countries, linking the possibility of migrating (brain drain) with incentives to higher education (brain gain). If emigration is...

The worldwide problem with pay-as-you-go (PAYG) social security systems isn't just financial. This study indicates that these systems may have exerted adverse effects on key demographic factors, private savings, and long-term growth rates. Through a comprehensive endogenous-growth model where...

Demographic change has differential impacts on the welfare of current and future generations. In a simple closed economy, aging -- a relative scarcity of young workers -- increases wages, increasing the welfare of the young. At the same time, population aging will reduce rates of return to...

The entitlement to social security retirement benefits is a major component of aggregate household wealth. This paper focuses on the impact of social security annuities on household portfolio allocation, extending existing optimizing models of portfolio allocation to explicitly consider the role...

"This ninth volume of the International Social Security series, which studies the social security and retirement experiences of 12 developed countries, examines the effects of pension reform on employment at older ages. In the two decades since the project began, a dramatic decline in men's...