Validation of Shojiro Ujihara's 'Closed Company Labor Market Model' : Re-analyzing the 'Keihin Industrial Area Survey'

Abstract

The purpose of this paper is to examine the three hypotheses proposed by Shojiro Ujihara in the early 1950's: the seniority system hypothesis, the long-term employment hypothesis and the closed company labor market (internal labor market) model hypothesis. For this purpose, the original completed survey sheets of the 'Keihin industrial area survey,' conducted by Ujihara in 1951, were investigated, transformed into data sets and analyzed. The findings are as follows: (1) The seniority systern hypothesis is partly supported by the fact that status and wage were determined by years of employment, although there were numerous exceptions, and the years of experience before employment also had certain effects on status and wage. (2) The long-term employment hypothesis is partly supported by the machine industry in the 1920's, the war-time era and the early 1950's. (3) The closed company labor market (internal labor market) hypothesis is almost completely disproved by the fact that there were many chances for mid-career leavers to enter large companies, especially in the prewar period.