Family size and life outcomes

What We Lose With Only Two Children Per Family by Andrew Yuengert.

Yuengert's main thesis is that we under-appreciate the practical mathematical reality attendant to family size. Do parents in your family tree usually have one, two, three, or more children? He uses the following table to make his point.

Click to enlarge.

From this, you can see that if the average family size in your tree is four children, then, at any particular point in time, there is a community of 45 people with whom you have familial ties. Granting that familial ties create some marginally greater intra-community obligations without exaggerating the nature of those ties, it is easy to see that that represents a potentially fairly robust safety net against the common vicissitudes of life. Robust especially compared to the familial safety net in the family where the average number of children is one. In that family, at any given point in time, the average number of people in your family community is 6.

For all that the common discourse is about the impact of discrimination and bias, I suspect all those effects, to the extent that they exist, are swamped by more mundane mathematical realities such as familial size.

Yuengert leaves his observation at a pretty high level, but there are all sorts of second order effects. I haven't seen any research but it would be interesting what the measurable impacts on individuals might be. For example, one could postulate that kids growing up in large households might have a more robust sense of self (they have to distinguish themselves in some fashion in order to stand out), might have a greater range and effectiveness of social skills (through constant practice), might be more tolerant of human variability, etc. than those who grow up in a single child household. Is that true? I don't know. It makes logical sense and it matches my own family anecdotal experience, but I don't know in any robust fashion.

Think of the financial implications as well. As generations age out, die and distribute their estate, what are the implications? A greater and greater concentration of wealth in the one child family and a dissipation of wealth in the large families. If X is the average estate, in the one-child family tree, that child can anticipate inheriting 3X (their parent's estate as well as the estates of each of their grandparents). In the four-child family tree, any one of the children can anticipate an inheritance of only 0.375X (0.25 from their parents and 0.125 from their grandparents). The current generation of the one-child family can anticipate eight times the inheritance compared to any one of the children from the four-child family. There's dramatic inequality for you, arising not from bias or discrimination but simply as the result of choices regarding family size.

Lot's of implied tradeoffs here. In the large family model, you potentially have a lot more noise, complications, obligations, impositions, variation and smaller inheritances. But you do get a lot more experience dealing with complexity, social variance, the unexpected, and you have some greater social safety net. In the small family model, there is greater predictability, simplicity, fewer obligations, less variation and much larger inheritances. But you have less experience dealing with the variety in the world, you are more alone and you have less of a safety net.

Which is better? The answer depends on normative values and goals and cannot a priori be answered without specification of terms, measures, and relative trade-offs.

In our shallow Gramscian postmodern, post-structuralist conversations with SJWs, I never see this very material fact of family size impact on statistical outcomes ever even mentioned, much less discussed.