Shelbyville High School, 30 miles southeast of  Indianapolis, is ground zero for Time magazine's Apr. 17, 2006 cover story on high school dropouts. The school's overwhelmingly white student body provides background for what the reporter calls "the most astonishing statistic in the whole field of education: an increasing number of researchers are saying that nearly 1 out of 3 public high school students won't graduate, not just in Shelbyville but across the nation."

No doubt too many blonde, crew-cut kids are not graduating on time. But the fact is that dropout rates for young whites have declined by over 50 percent in the past three decades, and are in the single digits. The really "astonishing" statistic, unemphasized by Time: the large fraction of Hispanics lacking a high school degree or its equivalent.

In Educational Industry jargon, the percentage of 16- to 24- year olds who are out of school and who have not earned a high school diploma or a General Educational Development (GED) degree is called the "status dropout rate." Status dropout rates in 2003 were as follows (Table 1):

If anything, these figures understate the education gap between Hispanics and other groups. More than half of young Hispanic immigrants never attended school in the U.S., but are counted as graduates if they obtained a degree in their country of origin—with no control for quality. (And even so, a whopping 41 percent of foreign-born Hispanics in the 16- to 24- year age bracket are dropouts.) [Status Dropout Rates by Race/Ethnicity (PDF)] Similarly, immigrants who enter the U.S. after age 25 are not counted in this dropout statistic.

Luckily (if that's the right word) the Census Bureau collects data on the educational attainment, nativity, and country of origin of all adult workers. This database goes back to 1940.

So what role does immigration play in long-term dropout trends?

Consider the data presented in a recent study of Mexican immigrants by Harvard economists George Borjas and Lawrence Katz (Table 2).

They calculate the percentage of adult male workers with less than 12 years of education, as follows:

Between 1940 and 2000 dropout rates for native-born male workers fell by almost 60 percentage points, and those of non-Mexican immigrants fell by nearly the same amount. By contrast, the share of Mexican-born males lacking HS degrees declined by only 30 percentage points.

"As a result of these trends," note Borjas and Katz, "the data indicate a remarkable fact: the population of male high school dropouts in the United States has become disproportionately Mexican-born. In 1940, 0.5 percent of all male high school dropouts were Mexican immigrants. Even as recently as 1980, only 4.1 percent of male high school dropouts were Mexican immigrants. By 2000, however, 26.2 percent of all male high school dropouts were Mexican born." [The Evolution Of The Mexican-Born Workforce In The United States]

Immigration enthusiasts find hope in the "native born" dropout trend. After all, this group includes children of Mexican immigrants. Over time, the immigration enthusiasts claim,  the English-speaking, U.S.-born descendents of today's Mexican immigrants will blend seamlessly into the mainstream.

But, as usual with immigration enthusiasts, this confident assertion turns out to be a myth.  In 2000, U.S.-born males of Mexican descent still had significantly higher dropout rates (21 percent) than native born non-Mexicans (8.3 percent). The college graduation gap is even wider.

To quote George Borjas in his 1990 book Friends Or Strangers: "Ethnicity matters. And it matters for a long, long time."

Why do Americans of Mexican descent remain educationally challenged? Is it culture? I.Q.? Lousy schools?

Borjas and Katz don't address this question, perhaps wisely.

But the real question is why taxpayers in Shelbyville have to subsidize this process at all—especially since it creates competition for their own children.

Edwin S. Rubenstein (email him) is President of ESR Research Economic Consultants in Indianapolis.