Interest rate risk, longevity risk and the solvency of life insurers

In this paper I assess the effect of interest rate risk and longevity risk on the solvency position of a life insurer selling policies with minimum guaranteed rate of return, profit participation and annuitization option at maturity. The life insurer is assumed to be based in Germany and therefore subject to German regulation as well as to Solvency II regulation. The model features an existing back book of policies and an existing asset allocation calibrated on observed data, which are then projected forward under stochastic financial markets and stochastic mortality developments. Different scenarios are proposed, with particular focus on a prolonged period of low interest rates and strong reduction in mortality rates. Results suggest that interest rate risk is by far the greatest threat for life insurers, whereas longevity risk can be more easily mitigated and thereby is less detrimental. Introducing a dynamic demand for new policies, i.e. assuming that lower offered guarantees are less attractive to savers, show that a decreasing demand may even be beneficial for the insurer in a protracted period of low interest rates. Introducing stochastic annuitization rates, i.e. allowing for deviations from the expected annuitization rate, the solvency position of the life insurer worsen substantially. Also profitability strongly declines over time, casting doubts on the sustainability of traditional life business going forward with the low interest rate environment. In general, in the proposed framework it is possible to study the evolution over time of an existing book of policies when underlying financial market conditions and mortality developments drastically change. This feature could be of particular interest for regulatory and supervisory authorities within their financial stability mandate, who could better evaluate micro- and macro-prudential policy interventions in light of the persistent low interest rate environment.