When a person retires, he or she may be the beneficiary of one or more retirement plans. The plans may be defined-benefit plans, in which the beneficiary knows the amount and timing of plan distributions with certainty. However, the plans may be defined-contribution plans. In these plans, the contributions are known, but the distributions are uncertain as to timing and amount. To reduce uncertainty, it is not unusual that a beneficiary of a defined-contribution plan would seek to take some or all of the pension assets and purchase an annuity contract. In doing so, the beneficiary would, in effect, convert an uncertain stream of payments into a certain stream. The beneficiary would reduce the risk of running out of pension assets prematurely, but at the cost of not being able to participate in higher payments that might occur in the future if the pension assets were invested well.