FACTORS OF INTERREGIONAL INCOME INEQUALITY IN POSTWAR JAPAN: THEIL DECOMPOSITION AND GAP ACCOUNTING ANALYSES

This study empirically identifies some factors of interregional income inequality in postwar Japan during the period 1955–2005 using a decomposition analysis with a Theil L index and a gap accounting analysis. One major empirical finding was that interregional inequality in per capita GDP during the period 1955–2005 showed a double peaked M‐shaped curve, which was predominantly attributed to interregional inequality in labor productivity. The sectoral decomposition analysis revealed that the factors that caused fluctuations in interregional inequality in labor productivity differed from year to year. The fluctuations during the period 1960–1980 were caused by an intersectoral equilibrating process between the tertiary sector and other sectors, whereas that the fluctuations that occurred in the late 1980s and early 1990s resulted from interregional disequilibrating and equilibrating processes within the tertiary sector.