Red-shirting the first grade, a good idea?

It is becoming increasingly popular to delay the entrance of children into first grade, or red-shirting them to use a term for university sports. The idea of parents is to give their offspring a competitive edge throughout their academic career as they would be more mature. While this should clearly work in the early grades, does this work for educational outcomes?

David Deming and Susan Dynarski claim it does not work, in fact there is even evidence that it is counterproductive. They show that red-shirted children make a slower progression through grades, going even as far as demonstrating that most of the slowdown in grade attainment over the past 30 years is due to the delay in school entrance. There is also a significant effect for the attainment of an undergraduate degree. Finally, delayed school entry also entails a shorter time spent thereafter in the labor force.

Why would parents still want to red-shirt their kids? They would clearly have advantages in non-academic areas: less subject to bullying, better at sports. In fact, I have heard the latter argument from other parents. While there is clearly an overemphasis on competitive sports in America schools (witness parents calling for less homeworks so the kids can train more), some argue that sports scholarships are the only way to finance a college education. School officials are also tempted by this practice, because it allows to have better students in a particular grade, and the school looks better in assessments.

While red-shirting does not seem to carry advantages for the children, it is a clear disadvantage for kids who enter school on time. They are typically of lower socio-economic status and face an even higher gap in the classroom. In this respect, this may also lead parents to red-shirt their children in order to avoid these disadvantages. This lead to competitive delays and a clearly negative outcome for society.