In this paper，we summarize and discuss the arguments behind using the time preference function，which assumes that an individual’s time preference rate is endogenously determined by their stock of health deficits，and we introduce a specific function that can reproduce the characteristics revealed in this discussion．There can be periods of weakening and strengthening of the present preference during an individual lifetime． The corresponding typical time preference curve shows a U‒shape throughout one’s lifetime．In particular，the decreasing phase of the discount rate in young adults is caused by hyperbolic discounting．On the Other hand，from the middle to elderly ages，the combined effects of aging and senescence lead to an increase in the rate of time preference．The characteristic time preference function so derived is implemented in a dynamic model that takes into account the health‒damage component，and its impact on the lifetime consumption profile is examined under different health‒related scenarios．Although each scenario is realistically possible，there are notable differences in the projected consumption profiles．
圭 細谷 (Sun,) studied this question.