On the Determinants of Internal Migration during the Bubble Period in Japan Using 1990 National Census Data by Sexes and Age Groups

Abstract

We analyze the determinants of internal long-distance migration in Japan from 1985 to 1990 (under the bubble period) by sexes and 5 years age groups using 1990 national census data. It is one of the most basic and important methods to analyze population phenomena by sexes and age groups. We have only a few preceding papers using this method in Japan however.The main models of this paper are (1) gravity model, (2) modified gravity model and (3) net migration model. We set the 10 major areas from 46 prefectures (we exclude Okinawa prefecture). We use the following variables as the independent variables: (1) P: size of population, (2) DS: physical distance, (3) IR: differentials of per capita real income, (4) LP: differentials of land price, and (5) variables of climate, AT; average temperature, SN; number of snow covered days, WDD; number of warming degree days, CDD; number of cooling degree days, DLH; daylight hours.The main results of our analysis are summarized as follows.(1) P and DS have strong explanation power for the number of internal longdistance migrants in Japan.(2) IR of destination areas shows weak but stable pulling power. Those of origin areas show different powers by age groups. Though IR of origin areas of 15-24 years old people has strong pushing power from low RI areas, that of age groups after retirement has pushing power from high RI areas.(3) Climate works people at cold areas go to warm areas, but the power is generally not prominent. It is shown that for age groups after retirements, high RI works to promote out-migration from metropolitan areas and low AT works to promote out-migration from cold areas. This phenomena is consistent with our findings that positive net-migrants after retirements are found out at Chugoku, Shikoku and Kyushu.