The productivity improvement effect of surrounding firms in the Japanese manufacturing industry ― industrial agglomeration and international trade ―

This paper aims to show that the productivity improvement effect of industrial agglomeration in the manufacturing industry in Japan is decreasing, while industrial infrastructure is maintained and international trade continues to advance. Industrial mesh data from 1990 to 2010 were used for the analysis. Because mesh data were used, it was possible to analyze the data by latitude and longitude. We found that the productivity improvement effect of industrial agglomeration was not clear in every case during the period studied and the effect of the agglomeration of firms was found to be decreasing in the manufacturing industry year by year. It is thought that increases in importing and exporting that result from the formation of the global value chain have influenced the gradual decrease in the effect of agglomeration. This decreasing productivity improvement effect associated with industrial agglomeration affects the creation of industrial clusters in Japan.産業インフラが整備され，産業の国際分業が進む中で，製造業事業所が集積することによる生産性向上効果を分析した。分析には1990年から2010年までの工業メッシュデータを用いた。メッシュごとのデータを用いたので市区町村の行政単位の再編の問題を避け，緯度経度での区割りで分析を行うことができた。その結果，製造業においては事業所が集中することの効果は明確ではなく，周辺事業所の生産性に対する効果は年々減少していることが明らかとなった。周辺事業所効果の減少には，国際分業による輸出入の増加が影響していると考えられる