Since the November election, there has been much talk in Washington and on the pundit circuit about America's changing demographics, especially the "Latino vote" and the new realities of political campaigning. There has also been considerable wrangling over immigration and what it means for a country that is a nation of immigrants but is more crowded than it once was.
The immigration debate is significant to America's politics and culture, but it is also crucial to the country's economics, a subject that...