Traditionally, one of the sources of America's advantage in wealth vis-a-vis the rest of the world has been higher overall levels of educational attainment. What's more, over time the overall level of educational attainment in the United States trended upwards. One of the most disturbing facts about the contemporary United States is that both of those trends have halted -- overall attainment levels have flatlined, and we've been overtaken by a number of other wealthy democracies. The causes of this remain somewhat mysterious, but (via Sara Mead) economists David Deming and Susan Dynarski suggest that the practice of so-called "Kindergarten Redshirting," where you keep your kid (usually a boy) out of kindergarten for an extra year so he'll be older than his peers and theoretically gain some kind of advantage, may be partially to blame:
Forty years ago, 96% of six-year-old children were enrolled in first grade or above. As of 2005, the figure was just 84%. The school attendance rate of six-year-olds has not decreased; rather, they are increasingly likely to be enrolled in kindergarten rather than first grade. This paper documents this historical shift. We show that only about a quarter of the change can be proximately explained by changes in school entry laws; the rest reflects "academic redshirting," the practice of enrolling a child in a grade lower than the one for which he is eligible. We show that the decreased grade attainment of six-year-olds reverberates well beyond the kindergarten classroom. Recent stagnation in the high school and college completion rates of young people is partly explained by their later start in primary school. The relatively late start of boys in primary school explains a small but significant portion of the rising gender gaps in high school graduation and college completion. Increases in the age of legal school entry intensify socioeconomic differences in educational attainment, since lower-income children are at greater risk of dropping out of school when they reach the legal age of school exit.
The basic causal mechanism, as Sara explains, is simple "Children (particularly boys) who are held back a year before entering kindergarten are a year older than their peers, which allows them to legally drop out of school a year earlier than they could have if they had started kindergarten when they were eligible, depressing educational attainment." Now individual choice plays a large role here so there's a limited amount policymakers can do to reverse this trend, but public policy does play a role here and we ought to try to make sure it's playing a constructive role.
Photo by Flickr user Leonid Mamchekov used under a Creative Commons license