那篇PAPER是这么写的:
This paper matches the 1% sample ofthe 1990 Population census with the 1989 CHNS at te county leve. The 1990 population census contains 52 variables including birth year, region of residence, whether an individual currently lives in his/her region of birth, sex, relationship to the head of the household and whether an individual is enrolled in school at the time of the survey. The data allows children to belinked to parents.
这明显是具体到了每一个数据吧?