The process of savings and investment creates a trade-off on the saver's value scale. It creates a disutility because of time preference, but also a utility because of the improved return on investment—that is, the increased production it makes possible in the long run. Crusoe's capital improvements will require him to consume less in the short run, but will enable him to consume more in the long run. He will save and invest only to the extent that the utility associated with greater long-term consumption exceeds the disutility of time preference on his personal value scale. Most individuals in most situations will maximize their value scale at some middle point—somewhere between the extremes of (a) postponing all consumption and investing all resources, versus (b) consuming all resources immediately and not providing for the future at all.

Time preference is universal, but it may be a greater or lesser influence on the value scales of different people. A person with six months to live and no heirs, for instance, will be likely to have extremely high time preferences, devoting most of his or her resources to immediate consumption or to production that leads to relatively near-term consumption. Because of differences in time preference between Crusoe and Friday, they may exchange present goods against future goods for mutual benefit, as in the following example.