Recently economists looked at the relationship between pupils' month of birth and their school performance. It was found that among fourth graders, the oldest children scored on math and reading somewhere between four and twelve percentile points better than the youngest children. That can be explained as a "huge effect." It means that if you take two intellectually equivalent fourth graders with birthdays at opposite ends of the cutoff date, the older student could score in the eightieth percentile, ___ the younger one could score in the sixty-eighth percentile.