Abstract
INAHSIM (Integrated Analytical Model for Household Simulation) is a micro simulation model, which was first developed in 1984-85 by using actual initial population and a set of transition probabilities derived from vital statistics and other national sample surveys. Among several attempts to improve the simulation model since 1985, a new application of the model has been made in 1993-94, which we call as 1994 Simulations. An outline of INAHSIM Model as developed in 1985 was first described briefly in this paper, with some characteristic features of the model. Although this paper mainly deals with the basic framework and main results of 1994 Simulations, some policy implications of the simulation were also discussed. In the analysis of households and families, applying INAHSIM to Japan, dynamic transition of household types was particularly focused. This paper is based on a new application of INAHSIM, where initial population of the model has been prepared by using the simulation model itself. In this way, it is confirmed that INAHSIM is applicable to countries where initial population is not available from census or national household surveys. Moreover, through this method, all problems caused by the initial population without the information about family members residing outside of the household will be avoided. New simulations were executed for the period of 1991-2040. In this model, family system is expressed by a set of probabilities, and by changing these variables, INAHSIM is able to apply to various kinds of family systems. Therefore, the outputs of INAHSIM are not limited to the information on the future number and composition of households. INAHSIM provides us, among others, information on dynamic transition of household types, the effects of family systems to the number and structure of households, and the household situation of the aged.
