boys and girls

Maybe parents treat their female and male children differently. Previous evidence indicates that parents spend more time with pre-teen sons than with pre-teen daughters, a difference that is caused by fathers spending more time with their sons.

Michael Baker and Kevin Milligan have new evidence that this extra time from fathers only emerges with age, and is not present when children are very young:

It is [pre-school] girls, not boys, who systematically, in three leading developed countries [i.e., Canada, the UK, and the US], receive more of these time inputs from their parents

But does this matter for academic achievement? They show that these differences in time are indeed important:

in each country the boy-girl difference in inputs can account for a non-trivial proportion of the boy-girl difference in preschool reading and math scores