Considering the substantial systematic longevity risk threatening annuity providers’ solvency, indexing benefits on actual mortality improvements appears to be an efficient risk management tool, as discussed in Denuit, Haberman and Renshaw (2011) and Richter and Weber (2011). Whereas these papers consider indexing annuity payments, the present work suggests that the length of the deferment period could also be subject to revision, providing longevity-contingent deferred life annuities.
Denuit, M., Haberman, S., & Renshaw, A. E. (2014). Longevity-Contingent Deferred Life Annuities (ISBA Discussion Paper 2014/35). https://hdl.handle.net/2078.5/195071