I just read this Demography paper by Benjamin G. Gibbs, Joseph Workman, and Douglas B. Downey for my work on the new edition of The Family (don’t hold your breath, but I’m working on it). It seeks to modify the traditional “resource dilution” model of explaining why children with more siblings end up with lower educational attainment, arguing that the effect depends on who else is sharing in the child rearing. Worth a read.
Anyway, since their 2016 paper only used the General Social Survey through 2010, I figured I could make a quick update through 2018. So this is based on their model, but a lot simpler — I didn’t impute missing values, and I didn’t include all the background variables (most notably parents’ education), or get into the religious context, which is the whole point of their analysis.
So, this is my result, showing proportion of people age 25 and older who have a BA or higher, by the number of siblings they have and the decade of their birth. These are average marginal effects from a model that includes race and age, as well as region, family structure (married parents), and religion at age 16.
I find no difference between 0 and 1 sibling, a little lower odds for those with 2 siblings, and then the proportion with a BA or higher drops off. The sibling effect has decreased, at least proportionally — for example, the 3-sibs to 1-sib ratio fell from 1.9-to-1 for those born in the 1910s to 1.4-to-1 for the 1940s to 1960s cohorts and even lower for the 1970s. However, the gaps crept back up in the years after Gibbs’ et al’s analysis ended, back to 1.5-to-1 for the 1990s cohort.
Some people who say getting married is good for kids so you should do it are also more-kids proponents. They should make their priorities clear.
I put the Stata code for this on the Open Science Framework, here.