Correct, it helps the farms remain profitable. My wife is a winemaker and even with the guest worker program they are not able to find enough workers. The salaries have gone above $20/hr, though the way overtime works is different and requires a lot more than 40 hours of work (for now). Don't have the time to put together a well referenced document, but the inability to hire workers at what I feel is above the value of the work is a real problem.

Two differences — and I’m not saying they’re “good” or “bad” because I refuse to claim I understand economics well enough — is that money flowing to undocumented workers is likely to be untaxed and money flowing to foreign citizens who neither live locally nor spend much locally will have some sort of impact on inflation, as there will be less currency circulating within the nation doing the employing.