The wondrous power of selection effects...

Latest SAT score data is out, and the first thing people look at is the race gap, of course:

Through the early 1990s and early 2000s, average scores on the SAT college entrance exam moved steadily upward. Now, for the last five years, they've been drifting back down.

The reason? Unlike on the multiple-choice sections of the test itself, there's no one right answer. But a big factor is the larger, more diverse group of students taking the tests, combined with a widening scoring gap between the best-performing groups and those whose numbers are growing fastest [cough, Mexicans, cough]...

The exception is Asian-Americans, whose average combined score surged 13 points to a combined 1623, while scores for whites fell 2 points to 1581. For black students, average scores dropped 4 points to 1276. Average scores for two of the three categories the College Board uses for identifying Hispanics also declined, and overall ranged from 1345 to 1364.

Well, gee, wonder why this is? Could it be...a good ol' selection effect? For the past decade, we've been admitting tons of South and East Asians to do technical and professional jobs (or because they are closely related to people who do those jobs), and tons of Hispanics to do menial physical labor...and then we turn around and act surprised that Asian scores are high and rising and Hispanic scores are low and falling! "Whatever Asian-Americans are doing, educators want to bottle it," the article goes on to say, but selection effects can't be bottled...

As for the ever-present white-black score gap, a lot of that is due to the fact that a large number of black kids grow up in broken families in poor ghettos, but that isn't the whole story...get ready for the most politically incorrect thing I've written (recently), but some of that just might be a selection effect too. Recall that most of the Africans who were brought to America were not brought here to be Harvard grad students, but rather to be the lowest of low-skilled slave labor...

Wow, did I just say that? But it's true. America is a country of immigrants, and we take different kinds of immigrants from different places. Unless we start accepting only grad students from Mexico and only gardeners from India, the "race gap" is here to stay. We might as well get used to it.

(Additional Fun Fact: Indian-Americans are the highest-achieving minority in America by far...we should increase Indian immigration tenfold!)