Risk sharing rules for longevity risk: impact and wealth transfers

In this paper, we consider pension plans in which actuarial gains or losses at the fund level are covered by adjustments of the accrued rights of the surviving participants. At the level of the pension fund, an actuarial loss (gain) arises if the number of participants that survived during the year is higher (lower) than expected at the beginning of the year, and/or if “best-estimate” projections of future mortality rates are adjusted downwards (upwards). It is common practice that institutes such as the Dutch Actuarial Society (AG) or Statistics Netherlands (CBS) frequently revise best-estimate projections of future mortality rates. Such updates can lead to non-negligible changes in the best-estimate value of pension liabilities.