Integrated Analytical Model for Household Simulation (INAHSIM) is a microsimulation model developed specifically for Japan. This model was initially developed in the first half of the 1980s as a tool for household simulation (Aoi et al., 1986 and Inagaki, 1986). Following several attemptsi to improve the model and to add socioeconomic characteristics of the population, the latest version of INAHSIMii has been utilized as a microsimulation model for policy simulation.
The key feature of this model is that it can simulate kinship relationships in detail. This model is not limited to parents, children, husbands, and wives, and can simulate all kinds of kinship relationships including those involving uncles, nieces, cousins, sons of separated parents, grandnephews, and great-grandnieces. This information is very important to simulate household changes in Japan since household mergers among family members—for example, adult children resettling to care for their aged parents or returning to their parents’ households following divorce—are common.
The kinship relationships are also important to determine the benefits of public assistance for the poor. Under the Public Assistant Law, certain relatives—for example, parents, children, grandchildren, and nephews/nieces—are required to support a person in need. The relatives are investigated as to whether or not they can support the person when the benefit of public assistance for the poor is claimed.