In a recent Southern Economic Journal article, Yezer and Thurston note that estimates of income differentials received by migrants that compare their post-migration wages to those of nonmigrants at either origin or destination may be biased because they do not incorporate the experience of migrants who did not remain at the destination. However, this is not the only selectivity bias to which such comparisons are subject. Ideally one should compare the post-migration wages of migrants to what they would have earned had they not moved. The latter, which cannot be observed, is often proxied by the wages of nonmigrants either at origin or destination. Using the origin wage of nonmigrants causes a selectivity bias, but it is even worse to use the destination wage of nonmigrants, as Yezer and Thurston do, since it may not even be systematically related to what migrants would have earned at origin had they not moved.