Evolution of Time Preference by Natural Selection: Comment
重新审视了Rogers（1994）关于时间偏好率生物学基础的分析，指出其使用的函数形式无法产生均衡演化行为，且内部解不一定出现，因此其关于实际利率约为2%的预测不成立。
We reexamine Alan R. Rogers' (1994) analysis of the biological basis of the rate of time preference. Although his basic insight concerning the derivation of the utility function holds up, the functional form he uses does not generate equilibrium evolutionary behavior. Moreover, Rogers relies upon an interior solution for a particular kind of intergenerational transfer. We show such interior solutions need not generally arise. Hence Rogers most striking prediction, namely that the real interest rate should be about 2 percent per annum, does not follow.