Question: Why do females tend to stay closer to home than males do when picking a college?
Do females stay closer to home than males? Maybe so, but that's a stat I've never seen. In fact, when I do a mental inventory of my own high school classmates and their college choices, harking back nearly four decades ago, the results don't support this conclusion. The two who journeyed farthest (to California, from our Philadelphia home turf) were both female. Conversely, more men than women went to the University of Pennsylvania close by, and the rest of the choices--near and far--were pretty evenly balanced between the genders.
But, let's just say that your hypothesis is correct ... then my best guess is that it's true for a couple reasons:
1) Mothers and fathers may be more protective of daughters than sons. I've counseled 12th-grade girls whose families didn't want them to leave home and live in dormitories. The parents urged them (or, in some instances, actually required them) to commute to college. In the case of these students I've known personally, they were first-generation Americans whose parents did not attend college themselves. Several had older brothers who did leave home for college.
2) In some families, it is still expected that male children will become heads of households and chief breadwinners so that they thus may be encouraged to attend the best possible college for preparation in their prospective career field, regardless of cost or location. For daughters in such households, however, being a wife and mother may be the primary expectation post-college. So girls may be pushed toward in-state public colleges with lower price tags.
I would conjecture that such thinking was more prevalent decades ago than it is now. But, as I noted above, in my own orbit in the Sixties, this wasn't true. However, the vast majority of my classmates came from affluent families with college educated fathers and mothers. I suspect that parents in this demographic were more open then (and still are) to their daughters flying far from the nest.