As Tom Joad in Steinbeck's novel discovered, many farmworkers, even as they spend their waking hours picking food for others, can barely afford to eat.

ECONOMIST: They came to America illegally, for the best of reasons

This is the difference between today's Mexicans and yesterday's Okies, between the Joads and the Vegas (although Tom Joad was also on the run from the law).

ECONOMIST: They came to America illegally, for the best of reasons