On Clemens's own reported results, the Mariel wage effect shrinks progressively as the race adjustment is loosened — roughly a third gone, then over half gone, then absent in the subsample where Miami's black share actually shifted

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Replicating Borjas's own regression framework, Michael Clemens reports a graded result rather than a single before/after comparison. Applying the simple, city-invariant race adjustment Borjas used, "about one third of the treatment effect disappears — but, as Borjas noted, not the entire effect." Allowing the black wage effect to vary by city (but not yet by education), "more than half the treatment effect is gone now, and the treatment effects are statistically insignificant relative to the Card control cities." Restricting that city-varying adjustment specifically to workers with less than a high-school education — the subgroup where, per Clemens's compositional argument, Miami's black-share shift actually occurred — "there is no wage effect relative to the Card control cities," though a smaller effect versus Borjas's own control cities (-5 to -8 percent) cannot be statistically rejected either way. A parallel check on the larger CPS Outgoing Rotation Group extract shows the effect disappearing even without the education interaction, once the black effect is allowed to vary by city alone.

The progression matters more than any single number: each successive loosening of the race-invariance assumption removes more of the estimated effect, and the loosening that removes the most is the one applied exactly where Clemens's compositional claim says it should bite hardest. This does not settle whether the loosening is correct — only that it is not ad hoc.