First, heterogeneity (heterogeneity)
Heterogeneity is actually what we often say about differences and differences. It can be at the individual level or at the group level. The former belongs to individual heterogeneity, while the latter belongs to overall heterogeneity. Heterogeneity is everywhere, which is also the real essence of social science research.
Second, testing and heterogeneity.
The purpose of quantitative social science research is to understand or recognize the main sources of heterogeneity, and one of the most important methods is social grouping. Therefore, we always use statistical analysis methods from the simplest T-test, variance analysis to more complex multiple regression analysis to help us do it more reasonably and scientifically.
Thirdly, heterogeneity analysis.
1, the simplest treatment is to include dummy variables. For example, women (0= male, 1= female) are included in the Mincer equation of wage income: Yi = β 0+β1Expi+β 2 edui+β 3 female II+ε i (where I stands for individual, exp stands for length of service, and represents years of education. )
2. The above equations correspond to two equations: for men, Yi =β0+β 1expi +β2edui+εi, and for women, Yi = (β 0+β 3)+β1Expi+β 2edui+ε i. It shows that the income of men and women is the same in length of service and years of education, but on average,