Big families are more conservative, but that doesn't affect public opinion much

These two articles looked at the relationship between fertility and social liberalism in Europe:They showed a paradox. Social liberals have fewer children than conservatives, but over time, Europeans have become much more socially liberal.To understand these dynamics, we really need to know whether social attitudes are handed down from parents to children. That requires a survey with at least two generations, which is quite rare. But there is a possible shortcut, which has less demanding data requirements: we can relate people’s opinions to how many siblings they have, instead of how many children. The idea is that, if conservative parents have many children and pass on their attitudes to them, then people with more siblings in the next generation will be more conservative. Better still, there is a neat trick to find out how strong this effect is: we can compare the actual distribution of opinions to a counterfactual distribution, where everybody has the same family size. I didn’t…