Research Database

This paper investigates why high income households in the United States save on average more than low income households in cross-section data. The three explanations considered are (1) age differences across households, (2) temporary earnings shocks, and (3) the structure of transfer payments. We use a calibrated life-cycle model to evaluate the quantitative importance of these explanations and find that age and the structure of transfers are quantitatively important in producing the cross-section pattern of United States savings rates. Temporary shocks are of secondary importance.

In this paper we examine the role of social security in an economy populated by overlapping generations of individuals with time-inconsistent preferences who face mortality risk, individual income risk, and borrowing constraints. Agents in this economy are heterogeneous with respect to age, employment status, retirement status, hours worked, and asset holdings. We consider two cases of time-inconsistent preferences. First, we model agents as quasi-hyperbolic discounters. They can be sophisticated and play a symmetric Nash game against their future selves; or they can be naive and believe that their future selves will exponentially discount. Second, we consider retrospective time inconsistency. We find that (1) there are substantial welfare costs to quasi-hyperbolic discounters of their time-inconsistent behavior, (2) social security is a poor substitute for a perfect commitment technology in maintaining old-age consumption, (3) there is little scope for social security in a world of quasi-hyperbolic discounters (with a short-term discount rate up to 15%), and, (4) the ex ante annual discount rate must be at least 10% greater than seems warranted ex post in order for a majority of individuals with retrospective time inconsistency to prefer a social security tax rate of 10% to no social security. Our findings question the effectiveness of unfunded social security in correcting for the undersaving resulting from time-inconsistent preferences.

Can neoclassical theory account for the Great Depression in the United States—both the downturn in output between 1929 and 1933 and the recovery between 1934 and 1939? Yes and no. Given the large real and monetary shocks to the U.S. economy during 1929–33, neoclassical theory does predict a long, deep downturn. However, theory predicts a much different recovery from this downturn than actually occurred. Given the period’s sharp increases in total factor productivity and the money supply and the elimination of deflation and bank failures, theory predicts an extremely rapid recovery that returns output to trend around 1936. In sharp contrast, real output remained between 25 and 30 percent below trend through the late 1930s. We conclude that a new shock is needed to account for the Depression’s weak recovery. A likely culprit is New Deal policies toward monopoly and the distribution of income.