本研究主要分析若市場沒有適當的長期投資工具避險，保險公司是否應提供具保證利率的終身壽險契約。本文認為就保單持有人的觀點，傳統具保證利率的終身壽險契約可能增加經理人的誘因將財富從保單持有人轉移給股東。具保證利率保單也可能增加代理成本（Agency Cost ofDebt）與保險公司的預期破產成本，而減少保險公司的價值。最後，保險公司也不能藉由投資在未發展的長期債券市場以減少利差風險。我們建議保險公司不應承擔投資風險，應由保單持有者承擔投資風險。保險公司應販售投資型保險（例如：變額壽險）減少投資風險，因為保單持有者承擔投資風險並享有投資報酬。

Our analysis indicates that traditional whole life insurance policies with guaranteed rates should not be issued from the perspective of policyholders because this type of policy increases the incentive for managers to shift the wealth from policyholders to stockholders. The guaranteed yield policies also increase agency costs and expected bankruptcy costs, which reduce the value of insurance companies. Finally, insurance companies are not able to reduce negative spread risk by investing in long-term bond markets, which are not well developed. We suggest that insurance companies should not bear investment risk. Rather, policyholders should bear the investment risk. Some types of policies such as variable life policies should be issued because policyholders bear the investment risk and enjoy the investment returns.