Here’s an interesting one about the unintended consequences of college admissions policies.

In 1996 a federal appeals court declared the affirmative action program then in effect for admission to the University of Texas unconstitutional. Barred by the courts from considering race in university admissions, the Texas state legislature moved to create an alternate, “race blind” mechanism for improving diversity in the UT system.

The solution the legislature crafted was a law, passed in 1998, providing that any student who graduated in the top ten percent of his or her high school class would be guaranteed acceptance to the UT school of his or her choice. This policy, it was expected, would increase UT enrollment from many schools with high proportions of poor students and students of color, and thus provide such students with greater opportunities — and incentives — for educational advancement.

That’s the background. Now here’s the story:

A new study looked at the effects of this policy, and found that it was having an effect not just on where students were going to college, but where they were going to high school as well. Promised UT admission if they graduated at the top of their class, a significant number of strong students were choosing to enroll in less-competitive local high schools over more intense magnet schools.

The first effect of this shift in enrollment should be obvious — those local high schools wound up getting an infusion of academically well-prepared students. Students who would ordinarily get cherry-picked by gifted and talented programs elsewhere were choosing to attend their local schools, improving those schools’ student bodies, their test scores, and — not incidentally — their attractiveness to other well-prepared students. In ordinary circumstances, no family, no student, wants to be the first of their peer group to attend a struggling school, but being the fifth, or the tenth, or the fortieth, is a different matter.

This is an outcome public school advocates strive for. This is a Good Thing.

But if you think about it for a moment, you realize that there’s a catch. Because if well-prepared students are attending struggling local high schools on the assumption that they’ll wind up at the top of their class, a good number of those students are likely to assume correctly. Which means that they’re likely to bump some of the students who would have attended those struggling schools without incentives out of the top slots.

And this is exactly what the new study found — that slightly fewer students of color wind up getting the ten-percent slots as a result of school shifting.

I haven’t had a chance to read the whole article yet — my request to buy it online got gummed up somehow — but I’ll have more after I do.