Pension Prefunding, Ageing, and Demographic Uncertainty

Pension prefunding can be used to smooth contribution rates in economies where ageing will increase pension expenditure. But how extensive should prefunding be in a defined benefit pension system when there is considerable uncertainty concerning future mortality, fertility, and migration? We study the prefunding rules in the Finnish earnings-related pension system with an OLG simulation model. The results show that increasing the degree of prefunding could yield a more even intergenerational outcome and make future generations' position better, but it is quite possible to overshoot and harm current generations too much. Making the degree of prefunding fertility-dependent appears to be a useful alternative. With declining fertility, current large cohorts would pay modestly increased contributions. The accumulated funds, however, will be huge in relation to the wage bills of smaller future cohorts.