Is this reasoning correct? If the changes were race-blind then it seems to me that we would not expect the same net change in incarceration rate, rather we would expect the same percentage change in incarceration rate. If I’m correct about this then the picture becomes quite different: while both races experienced increasing rates of incarceration, in all three categories the percentage change was higher for whites than for blacks.

Yes, that’s right. It depends whether you focus on how the percentage change in the incarceration rate differs between groups, or on how the total percentage of the population incarcerated differs between groups. In the former case, the rate of growth was a bit higher for whites. As Western et al say in their paper, The table shows that the rate of growth in incarceration was slightly faster for whites than blacks. Thus racial disparity in imprisonment, measured by the black-white ratio in incarceration rates, declined slightly from 1980 to 1999. The Prison Boom incarcerated many whites as well as blacks between 1980 and 1999, of course. But I was trying to say that this growth process disproportionately affected blacks because such a higher percentage of them ended up being incarcerated as a result of it. Western et al again: Even so, black men between the ages of 18 and 65 were nearly 8 times as likely as whites to be in prison or jail in 1999. Despite small declines in racial disparity, the largest absolute gains in incarceration were recorded by black men. Racial disparity in incarceration is partly ex-plained by the relatively low level of schooling of young black men compared to young whites. If we look just at high school dropouts, the black-white ratio in incarceration rates is just half as large as for the population as a whole. Even among dropouts, however, blacks remain four times more likely to be in prison or jail than whites. So I think it’s still true to say that whatever drove the increase in the prison population disproportionately affected young, unskilled and especially black men. But you were right to point out that I could have expressed it better (as Western et al in fact did).

I’ve written about the intersection of incarceration, race and the labor market several times in the past. In the United States, the remarkable expansion of the prison system over the past thirty years, despite generally falling crime rates, has …