Labor Mobility
YouNotSneaky! points out (”How much of a jerk do you have to be to oppose immigration?“) that a low-skilled worker can make $9.34 an hour in America, compared with just $2.56 in Mexico. He assumes that migrants depress the wages of low-skilled Americans by 5% — a widely cited estimate. To justify opposing immigration, the blog concludes, you must attach at least 20 times more weight to the well being of a native-born American than to a Mexican.
Gordon Hanson points out (”The Economic Logic of Illegal Immigration” — .pdf file here) that since 1960 the share of native-born workers with less than a high-school diploma has fallen from 50% to 12%. Some 24% of farm workers, 17% of cleaners and 14% of construction workers are illegal aliens.
A study in the 1990s showed that a 10% drop in Mexican pay relative to US wages prompted a 6% increase in attempts to cross the border. Recently, a slowdown in remittances to Mexico and other Central American countries suggests the housing bust, and home-building slump, may have reduced the pace of illegal immigration.