Social Econ Blog

In late November, a friend of mine had his second child. Had little GKE clung to the womb for a couple more days, he would have improved his expected school performance dramatically. California, where his parents currently live, has a December 1 cut off date for school eligibility. Thus, little GKE (should his parents enroll him when he's eligible) will be the youngest member of his school cohort, and when it comes to childhood human capital acquisition, older is better.

The Freakonomics guys highlighted the link between age cutoffs and sports last summer. They pointed out that after FIFA introduced a Jan 1 age cutoff the birth month distribution shifted from pretty uniform to heavily weighted in the early months of the year. Allan and Barnsley (1993) show a similar effect among Canadian hockey players. Both sets of authors argue that because they are nearly a full year more developed than their younger counterparts, older children receive favorable treatment from coaches (e.g., being selected for teams). These small boosts in their early skill acquistion are compounded over time.

Further, as discussed previously, Elizabeth Dhuey and Stephen Lipscomb argue that school age cutoffs affect individuals propensity to assume high school leadership positions. Ms. Dhuey (working with Kelly Bedard) also finds evidence for this phenomenon in academics. In an article published in the November QJE, they:

provide substantial evidence that these initial maturity differences have long-lasting effects on student performance across OECD countries. In particular, the youngest members of each cohort score 4-12 percentiles lower than the oldest members in grade four and 2-9 percentiles lower in grade eight. In fact, data from Canada and the United States show that the youngest members of each cohort are even less likely to attend university.

Thus, while little GKE certainly has good genetic material and parents who I am certain will invest extensively in his human capital, they may need to make some specific adjustments to account for these age effects. For instance, they can abandon the beach and move north to Oregon where the school cutoff is November 15.