Let me first try to clear up a few misunderstandings. I did not suggest that competition from illegal immigrants working in the United States was bad or inefficient. The more competition in labor markets, the better. Nor was I defending restrictions on immigration. I do not believe in unrestricted immigration, because the result would be such a flood of immigrants that the congestion and other external costs imposed, along with the inevitable political and social strains, that the costs would exceed the benefits. But I do think that we should encourage immigration, especially but not only of highly skilled workers. In our postings, Becker and I were assuming that there are laws restricting immigration, whether good or bad laws, and asking how they can best be enforced. I strongly disagree with the comment that complained about the "flotsom [sic] and jetsam" of the world's population being washed up on our shores. Most illegal immigrants are Mexican, and they are hard workers with strong family and other values compatible with U.S. culture. Most immigrants from other nations either have special skills that are in short supply in our nation or are refugees seeking asylum from regimes that have persecuted. I believe both classes of immigrants are positive additions to American society. That comment also accused Mexican illegal immigrants of being disproportionately involved in crime. An article last week in the New York Times reported the opposite--that they are less likely to commit crimes than members of other groups. That makes sense, since an illegal immigrant who commits a crime obviously greatly increases the likelihood of being deported. What is a true observation in the comment and what I should have mentioned in my original post is that the costs imposed by illegal immigration are distributed quite differently from the benefits, which may explain the strong anti-immigrant sentiment in some parts of the nation. The federal fisc is enriched by illegal immigration, because most of the immigrants pay social security taxes but are not eligible for social security benefits (or Medicare), and consumers as a whole benefit from the lower labor costs that result from a larger labor supply due in part to illegal immigration. But because the Supreme Court has held that it is unconstitutional to deny a free public school education to children of illegal immigrants, local school systems (and other local government service providers) incur additional costs as a result of illegal immigration that they do not recover in taxes. This is an imbalance that could be corrected by the federal government's providing financial aid to those schools, in recognition of the "profit" that the federal government earns from illegal immigrants because of their disentitlement to federal benefits. My guess, though, is that much or all of the added costs of local government that illegal immigrants impose are offset by the benefits that the immigrants confer on the local community in filling jobs in hotels, restaurants, and agriculture that American citizens do not want. One comment questions my suggestion that the Constitution might not require that children born in this country of illegal-immigrant parents automatically receive U.S. citizenship. It is true that section 1 of the Fourteenth Amendment provides that ‚Äúall persons born or naturalized in the United States, and subject to the jurisdiction thereof, are citizens of the United States and of the State wherein they reside.‚Äù But the purpose of this provision, adopted in 1868, was merely to grant citizenship to the recently freed slaves, and the accepted exception for children of foreign diplomats and heads of state (such children, though born in the United States, do not receive U.S. citizenship), shows that the citizenship clause need not be read literally.