Generational equity and social insurance.

In recent years, critics have argued that, when inter-generational transfer programs such as Medicare are judged by the standard of "generational equity", these programs are seen to be unfair. It is argued that, under a pay-as-you-go system, future generations are committed to burdens without their consent; that claims are not contractually guaranteed; that early entrants reap windfalls gains; that successive cohorts are tempted to provide insupportably high benefit levels; and, finally, that fluctuations leave future generations at unacceptable risk. Attempts have been made to defend social insurance programs by means of a "lifespan prudential model" of age-group resource allocation, but this defense does not adequately take account of uncertainties and inequities faced by historical birth cohorts. A deeper defense must acknowledge an element of risk-sharing and solidarity while trying to limit inequities within reasonable bounds.