摘要：The study described in this short paper sets an elderly care model in which the public elderly care and informal elderly
care provided by the family are substitutive, with examination of the dynamics of capital accumulation and the labor
supply. By virtue of capital accumulation, informal elderly care is reduced by public elderly care. With certain
conditions, by virtue of public elderly care, informal elderly care vanishes and a full labor supply is achieved.
However, this paper presents derivation of the result that the economy with informal elderly care is socially optimal.
