Resources are reallocated across age and time by means of capital accumulation, credit transactions, and transfers. Each takes place through three channels: the family, financial markets, and public sector programs. These age-specific flows give rise to stocks of age-specific wealth. Weighting...

The US population will age rapidly for several decades and then more slowly, with less aging than most rich nations. Health of the elderly has greatly improved, but disability stagnated after 2000. Retirement age reversed its decline in the mid-1990s and health status leaves ample room for...

We present forecasts of the Social Security trust fund, modeling key demographic and economic variables as time series. We evaluate plans for achieving long-term solvency by raising the normal retirement age (NRA), increasing taxes, or investing some portion of the fund in the stock market....

Abstract At each age an organism produces energy by foraging and allocates this energy among reproduction, survival, growth, and intergenerational transfers. We characterize the optimal set of allocation decisions that maximizes fitness. Time preference (the discount rate) is derived from the...