Evolution of Time Preference by Natural Selection: Comment

摘要

aspects of his model that do not hold up. The first of these is that the reproductive value he uses is not general enough for the present circumstances. The expression he gives for the utility function is correct only in its basic additive form. The second issue is that there will not generally be interior solutions for "same-age transfers." Although the one-half degree of relatedness between mothers and daughters does play an important role in determining the marginal rates of substitution between consumption now and consumption in the future, the theoretical situation here is more complex than described by Rogers. The most striking conclusion of Rogers-a particular real rate of interest-does not generally follow.