Changes of Unequal Structure of Stratification in Modern Japan

通过分析日本社会流动性中机会不平等的时间变化，区分时间效应、队列效应和年龄效应，得到了以下结果。通过Logistic回归模型和对数线性模型的分析，明确了这三点对机会不平等(阶级继承倾向)的估计。首先，机会不平等随着年龄的增长而减少的趋势很明显。第二，由于时期效应和队列效应的复合变化，一个社会作为一个整体所拥有的不平等机会的总和已经减少和均等。第三，代内流动对代际流动中的机会不平等有一定的均等化作用，在不同的阶层，特别是个体户阶层，机会不平等表现为向入门阶层流动和向当前阶层流动的机会不平等表现出不同的时间变化，并有不同的变化因素。在流动到进入阶层中，机会不平等的总和通过队列转移导致的农民继承的快速减少而均等化，人口在阶级中的分配显著改变为从父亲的阶级继承中选择的受教育程度的分配。与向入门阶层流动相比，年龄效应降低了向当前阶层流动的机会不平等程度。这意味着代际流动性被代内流动性所平衡。从分析结果看，日本社会机会不平等表现为农民减少、分配原则通过学历向阶层渗透以及代内流动的均等化效应在20世纪90年代以前的均等化变化。

The following findings were obtained as a result of the analyses to detect temporal changes of unequal opportunity in social mobility of Japanese society, distinguishing time, cohort, and age effects. The three points became clear by the analyses of logistic regression model and log linear model to estimate unequal opportunity (tendency of class inheritance). First, the tendency that unequal opportunity decreases as age increases was salient. Second, the sum of unequal opportunity which a society has as a whole has been reduced and equalized as a result of compounding changes by period effect and cohort effect. Third, intra-generational mobility has an effect to equalize unequal opportunity in inter-generational mobility, in several classes, especially self-employed classes.After all, unequal opportunities in mobility to entry class and in mobility to current class have carried out different temporal changes and have different factors to change, each other. In mobility to entry class, the sum of unequal opportunity was equalized by rapid decrease of farmer's inheritance according to cohort transition, and the distribution of people to classes was remarkably changed into one selected by educational credential from inheritance of father's class. The level of unequal opportunity in mobility to current class was reduced by age effect in comparison with that of mobility to entry class. This means that inter-generational mobility was equalized by intra-generational mobility. As for the result of analyses, unequal opportunity in social mobility of Japanese society showed changes equalized till the 1990s according to reduction of farmers, penetration of the distribution principle to entry class by educational credential, and the equalization effect by intra-generational mobility.