I. Abstract This abstract consists of a concise list of conclusions from the analysis in this paper. A. Assessing Recent Official US Vital Rate Forecasts • In retrospect, it appears that over the last fifty years, the Census and Social Security forecasters attached too much importance to the most recently observed levels of fertility and mortality. • Recent Census Bureau projections of US fertility, based on race/ethnic disaggregation, appear to be too high. Recent Social Security fertility

more »

... ections appear reasonable, although the range may be too narrow in light of international experience. • Recent projections of life expectancy gains by both Census and Social Security appear to be substantially too low, in light of past US experience and international levels and trends in low mortality countries. B. Uncertainty in Population Forecasts • The standard method for dealing with uncertainty in demographic (and many other) forecasts is the use of high, medium and low scenarios. This approach is deeply flawed, because it is based on very strong and implausible assumptions about the correlation of forecast errors over time, and between fertility and mortality. The random scenario method is an improvement, but it retains some of the same flaws. • Raising the normal retirement age to 71 by 2023 raises the median long term actuarial balance above 0 in LT stochastic forecasts, but still leaves a 43% chance of fund exhaustion before 2070.