As the U.S. population ages, the growing retiree-worker ratio increases the burden of public retirement systems. Is it efficient to maintain a defined benefit social security system? Should PAYGO benefits be reduced and private retirement savings be encouraged? The paper examines these questions in a neoclassical growth model with overlapping generations and demographic uncertainty. In case of shocks to the birth rate, I find that a defined-benefits social security system is more efficient ex-ante than a defined-contribution or privatized system. This is because small cohorts generally enjoy favorable wage and interest rate movements. They are in the labor force when the capital- labor ratio is high and they earn capital income when the capital-labor ratio is low. A defined benefit system helps to offset the effect of these factor price movements by imposing higher taxes on small cohorts. Neither defined-benefits nor its main alternative are fully efficient, however, because they all fail to adjust current retiree benefits in response to anticipated future demographic changes. In case of changes in life-expectancy, the efficient policy response depends on the predictability of deaths at the individual level and on the availability of annuities. Reduced benefits can be efficient if annuities markets are missing and the mortality change is such that accidental bequests decline, but not otherwise

The United States is in the midst of a major demographic shift. In the coming decades, people aged 65 and over will make up an increasingly large percentage of the population: The ratio of people aged 65+ to people aged 20-64 will rise by 80%. This shift is happening for two reasons: people are living longer, and many couples are choosing to have fewer children and to have those children somewhat later in life. The resulting demographic shift will present the nation with economic challenges, both to absorb the costs and to leverage the benefits of an aging population. Aging and the Macroeconomy: Long-Term Implications of an Older Population presents the fundamental factors driving the aging of the U.S. population, as well as its societal implications and likely long-term macroeconomic effects in a global context. The report finds that, while population aging does not pose an insurmountable challenge to the nation, it is imperative that sensible policies are implemented soon to allow companies and households to respond. It offers four practical approaches for preparing resources to support the future consumption of households and for adapting to the new economic landscape.

Social Security Policy in a Changing Environment analyzes the changing economic and demographic environment in which social insurance programs that benefit elderly households will operate. It also explores how these ongoing trends will affect future beneficiaries, under both the current social security program and potential reform options. In this volume, an esteemed group of economists probes the challenge posed to Social Security by an aging population. The researchers examine trends in private sector retirement saving and health care costs, as well as the uncertain nature of future demographic, economic, and social trends—including marriage and divorce rates and female participation in the labor force. Recognizing the ambiguity of the environment in which the Social Security system must operate and evolve, this landmark book explores factors that policymakers must consider in designing policies that are resilient enough to survive in an economically and demographically uncertain society.

The Committee on National Statistics and the Committee on Population, at the request of the NIA, convened a workshop in March 1996 to discuss data on the aging population that address the emerging and important social, economic, and health conditions of the older population. The purposes of the workshop were to identify how the population at older ages in the next few decades will differ from the older population today, to understand the underlying causes of those changes, to anticipate future problems and policy issues, and to suggest future needs for data for research in these areas. The scope of the workshop was broader than that of the 1988 CNSTAT report, including not only data on health and long-term care, but also actuarial, economic, demographic, housing, and epidemiological data needs for informing public policy.

In this paper, I analyze consumption, aggregate savings, output and welfare implications of five different social security arrangements whenever there is demographic uncertainty. Following Bohn (2002), I analyze the effect of an uncertain population growth in an extended version of a modified Life-cycle model developed by Gertler (1999). Population growth dampens savings and output under all arrangements. Pay-as-you-go-Defined Benefit system appears to fare better than all other alternatives, falling short of the private annuity market with no pension system. But social security in general increases social welfare, with Fully Funded systems faring the best. Thus there appears to be a clear trade-off between growth and social welfare. The social security system also reduces the volatility of the economy.

This volume addresses the most important issues of the ongoing discussion on designing social security. It provides fundamental results for pay-as-you-go social security, covers the issues of social security during demographic transition and examines the inclusion of risk aspects into the analysis of social security. An empirical case study of Germany yields the surprising result that de facto the German public pension scheme already comprises an implicit demographic factor. This book allows a subtle understanding of how interacting risks are treated within different pension systems and thereby provides a basis for the development of innovative ways of risk sharing.