Be careful of some claims that life is getting better for black males

All this seems pretty obvious to me, and it is hard to believe that people would measure the high-school drop out rate by not looking at the entire black population of that age group.  From the WSJ:

That has significant implications for evaluating the progress of black Americans, according to a book published this past week. The number of incarcerated Americans has grown far quicker than the general population, and today a large-enough portion of young black men are behind bars to skew findings by surveys that omit them, the author says. 

Among the generally accepted ideas about African-American young-male progress over the last three decades that Becky Pettit, a University of Washington sociologist, questions in her book "Invisible Men": that the high-school dropout rate has dropped precipitously; that employment rates for young high-school dropouts have stopped falling; and that the voter-turnout rate has gone up. . . .