Extraordinary longevity: individual and societal issues.

The likelihood of substantial increases in average life spans and the potential for profound longevity increases (to 100, 110, or 120 years on average) raises a host of societal issues. These include huge increases in the number of old and very old persons, the likelihood of a massive increase in health expenditures for the population aged 65 and older, the potential for outliving financial resources, challenges to the viability of Social Security and pensions, concerns about quality of life, and possible intergenerational antagonisms. If marked increases occur in average life spans worldwide, several billions could be added to world population at eventual stability, and that could become a sustainability issue. To prepare for what is likely to be our demographic future requires a major shift in thinking about this type of complex issue; we must change from a simple linear to a much broader systems approach. Changes in retirement age, strengthening (but then replacing) the Social Security system, retaining older persons in the labor force, mandating retirement savings during working years, and many other actions must be considered in a debate that should start now about life span increase and the future; if we dawdle, we risk the consequences of being unprepared for the dramatic demographic changes that are likely to occur in the coming decades.