Michael at 2blowhards.com asks a good question:
If illegal immigration from Mexico is inevitable, as some make it out to be, then why was there so little illegal immigration from Mexico prior to the mid-1960s?
The composition of Mexican immigration has changed dramatically. Go to El Paso, where many Mexican-Americans have been around for a few generations, and you will see mostly mestizos. Over time, more of the immigrants come from deeply rural Mexico. Often they cannot read or write, their knowledge of Spanish (never mind English) is rudimentary, and they have no idea of decent medical care. They will get a witch doctor to boil corn for a divination. For them, coming to the United States is a major and new encounter with Mexican culture, never mind Yankee culture.
This is one reason why current Mexican immigration is bringing more social problems than before; it is not just the numbers. Nor is there much solidarity amongst immigrants, many of whom hold cultural grudges based on disputes from back home. One acquaintance of mine returned to his home village about two years ago, complaining of "all those Mexicans" in Los Angeles.
Contrary to economic intuition, it is often the poorest migrants who leave last. If I think about the Mexican village where I hang out and buy art, only in the last twenty years has anyone had enough money to catch a bus to the border, much less pay the "coyote" fees to cross. Mexican immigration also works as a chain. One person crosses the border, finds a job, and sends money back so that brothers and friends can cross as well. For all these reasons the flood is, for better or worse, now much harder to stop. As Mexico gets richer, more people are coming.
Intertemporal substitution is especially important for these new migrants. If it were easier to come and go, many Mexicans would spend a big fraction of the year in their home villages. The burden on the U.S. would become less in some ways, more in others. In the U.S., jobs would be more temporary, more Mexicans would live near the border (for easy regular transport), Mexicans would work harder in their time here (and consume their leisure back home in the village), and most importantly, more Mexican males would keep ties to their wives and families. The net effect might well be positive.
If you would like to read more about this, I recommend my own Markets and Cultural Voices: Liberty vs. Power in the Lives of the Mexican Amate Painters.
My next question: Do you think that migration from Bhutan is high or low? Do you have the intuitions of an economist or sociologist? Answer here. Hint: it won’t stay low forever.