Children's highest years of schooling has a different effect on life equality during different periods of old age.
Compared to increasing children's average years of schooling, increasing children's highest years of schooling has a more significant and positive effect.
The life quality of elderly parents will increase more when children achieve the highest years of schooling, as compared to the average years of schooling.
Upon distinguishing the quantity and gender of children, we further categorize the years of schooling into average years of schooling, lowest years of schooling, and highest years of schooling.
When examining the living environment, we find that daughters' and sons' highest years of schooling affect elderly parents' life quality differently.
Daughters' highest years of schooling has a significant positive effect not only on elderly parents' relative economic status but also on their meat consumption.
However, the number of children cannot affect the children's highest years of schooling directly; in other words, parents cannot decide on children's highest years of schooling by manipulating the number of children they can only collect their resources and send their children to school.
If we look at the living pattern, we can see that there is a positive relationship between daughters' highest years of schooling and parents' living with children, although it is not significant, while there is a significant negative relationship between sons' highest years of schooling and parents' living with children (p = 0.001).
No matter whether it is the children's average years of schooling or their highest years of schooling, the positive relation exists, suggesting that the effect of education is very stable.
Therefore, the above two indicators are also used to measure the "fewer and better birth" policy and to use the highest years of schooling of sons and daughters to indicate parents' resource concentration strategy.14.14
