I was 22 so 23 doesn’t seem out of line. Especially for children of immigrants who may be placed below their age group when first enrolling in e.g., elementary school in the U.S. That could simply reflect an assessment of their skills in the English language at that time.

I suppose a more general reason for lengthening the time to graduate college is the increased cost. That probably means more students today hold down jobs to help pay tuition and may also mean lighter academic loads. I don’t quite get the logic of paying a full semester’s tuition for less than a full academic load, but if one can’t afford it without the job, maybe that happens.

This is mostly guessing on my part. I’m looking for data about this – but unsuccessfully so far. Anyone?