Expanding Disparity and Polarization of Metropolitan Areas after 1980s

In Japan, expansion of economic disparity started at about 1980. This expansion was accompanied by the polarization of Metropolitan Areas. In Tokyo, economic disparity of 23 wards expanded rapidly in 80s. However this disparity reduced temporarily in first half of 90s, because of collapse of bubble economy, expanded again in last half of 90s, and expansion continues until today. In this processes of expansion of economic disparity, socio-spatial structure of Tokyo has changed. On the base of 4-classes scheme, which consists of capitalist, new middle, working and old middle classes, these changes are analysed. From 80s, old middle class dramatically decreased in whole area of Tokyo, especially in central and inner city areas. And in 90s, capitalist class started to decrease in whole area of Tokyo, especially in central area. In these processes, composition of old middle class and capitalist class changed, from family business to one-man management and corporate business. In the result, population of central and inner city area decreased in 80s and 90s. In 00s, new middle class started to flow in central and inner city areas. They filled up the blank of old middle class and small capitalist class, and became the new central player of Tokyo. However this chain of processes can be called gentrification, in the sence that there was some time lag between the exit of old player and emergence of new player, this may be called ‘time-lagged gentrification’, which means bloodless revolution by new middle class.