Appropriate bus attire

You have to pull your pants up on buses in Fort Worth,Texas these days, lest some passenger be offended by the sight of your boxers.

Yes, to be sure, the saggy trouser "look" looks pretty stupid - more like a failure to reach the bathroom in time than a style statement - but that is hardly sufficient reason to ban it. Big earrings from the 70s look stupid too and, oftentimes, those spandex pants are a big (pun intended) sartorial mistake as well. Part of being a grown up in public spaces is putting up with the misguided style choices of others.

Surely the people who manage the transit system in Fort Worth have something more useful, and less racially tinged, to do with their time?

Hat tip: Charlie Brown

School desegregation and adult health

I've been meaning to blog for a while that I quite liked this paper by Rucker Johnson that I saw him present at the Institute for Research on Poverty Summer Research Workshop this past June.

The thing that struck me about the results , that is not emphasized that much in the paper, is that he finds that being subject to school desegregation, in addition to positive effects on blacks, does not have much in the way of effects on whites. Given all the upset at the time about the school desegregation, this is surprising, if only because it must have been a stressful experience for all the students involved.

Intermarriage in the US

Alert reader (and UM economics Ph.D.) Jon passes along a pointer to a recent Pew study on intermarriage in the US in response to my earlier post on intermarriage in Canada.

The rates are much higher than I would have thought, particularly for blacks. The aysmmetry in intermarriage rates between black men and black women is large and has important implications for the "marriageable men" theory of William Julius Wilson. Indeed, I long intended to write a paper on just that point but never got around to it. That's another free paper idea ...

The geographic differences are interesting as well, though that one case where the multivariate analysis would be of interest, as Asians in the US are concentrated on the coasts and are generating a lot of the intermarriage. More broadly, there is a great "economics of intermarriage" paper waiting to be written as well, I suspect ...

Intermarriage in Canada

These statistics were on the front page of the National Post, with no accompanying article, a few weeks ago when I was in Ottawa for a one-day conference on the Canada Student Loan Program.

The percentage of mixed couples for black Canadians is particularly notable and, I suspect, much much higher than the corresponding rate in the US. An interesting question is whether this results from differences in preferences between the two countries or from the fact that, both relatively and absolutely, blacks represent a much smaller fraction of the population in Canada, and so have a smaller within-group choice set. Of course, it could be some of both.

That's a free paper idea ...

When random assignment yields implausible estimates

Consider the following educational treatment, as described on the Department of Education's What Works Clearinghouse:

Seventh graders were placed at random into intervention and comparison groups near the start of the school year.

Both groups were given structured writing assignments three to five times during their seventh- and eighth-grade years.

The intervention group wrote about their personal values (e.g., relationships with friends and family, religious values) and why these were important to them.

The comparison group wrote about neutral subjects, such as their daily routine, or why values they considered unimportant might be important to others.

The result? The WWC summarizes the findings:

Among African-American students, completing writing exercises about their values increased their average seventh- and eighth-grade GPA by a quarter of a letter grade (0.24 points), a change that was statistically significant. The intervention did not have a statistically significant effect on the academic outcomes of European-American students.

Among low-achieving African-American students, the effect was somewhat larger, an increase in average seventh- and eighth-grade GPA of 0.41 points. In addition, the intervention reduced the likelihood that low-achieving African-American students were assigned to a remedial program or were retained in grade.

Is this plausible? Both 0.24 and 0.41 GPA points are large impacts, particularly given that the support of the GPA distribution at many schools is largely confined to 2.0 to 4.0 or even 2.5 to 4.0.

What could go wrong? Like most educational interventions, this one is not double-blind. It may not be single-blind either, if the teachers know which students ended up in the treatment and control groups. On the other hand, given that all students wrote essays it may not have been clear to the students what the "treatment" was in some sense.

One might also worry that one of the alternative essay topics, namely "why values they considered unimportant might be important to others" is not really "neutral" and instead might have its own treatment effect. In this regard, it would be nice to have a no-essay control group along with the "other essay topic" second treatment arm. A no-essay control group has its own issues, of course, because it makes the nature of the treatment clearer to the students, but it would shed at least some light on concerns that one of the alternative essay topics may reduce GPAs rather than the other increasing them or some combination of the two.

Also, one would like a compelling theory of why such a modest treatment should have such a gigantic effect.

Interesting, and puzzling, and a good illustration of why one study is rarely definitive and, not unrelated, why good science involves both exact replications and small perturbations of provocative results.

I should have gotten one of my ECON 490 students to do their literature survey on such treatments.

Only shades of gray ...

There is an old Monkees' song called Shades of Gray, the chorus to which is

But today there is no day or night
Today there is no dark or light.
Today there is no black or white,
Only shades of gray

This WaPo article on Obama's blackness, or rather his partial lack of blackness, reminded me of that song, as well as of Ursula LeGuin's novel The Lathe of Heaven, in which the protagonist can affect the world with his dreams. He starts to try to consciously manipulate this power; his attempt to end racism in this way succeeds as when he awakes everyone is gray. This is portrayed in the novel, as I recall, as something of a negative, but that is not so clear to me.

It strikes me that inter-marriage is the one sure-fire solution to racial and ethnic separation and discord. I am glad to see it rising in the US and extending to groups where historically it has been low, such as blacks and whites, as well as continuing in cases where it was already high, as with whites and Asians. This is just the melting pot, doing its good work.