Commuting and spatial structure in Japanese metropolises

In this paper we extend an approach by Merriman, et al. (1995) to time-series data of commuting flow in Tokyo, and 1990 commuting data in other Japanese metropolises. We find that spatial structure of Tokyo Metropolitan Area is going toward US cities like LA, but smaller Japanese metropolises still have concentrated spatial structures and less excess commuting than four major metropolises. Discrepancy seems to be explained by differences in urban structures and so far.