Daniel Griswold, "Comprehensive Immigration Reform: What Congress and the President Need to Do to Make it Work," Albany Government Law Review 3, 1 (2010).
This article is part of a special issue examining immigration from a variety of different angles. It does not really break any new ground, but provides a very nice overview, particularly from a demographic perspective. Further, it reiterates some key points that I wish were more widely known. Probably the best book laying it all out is Massey, Durand, and Malone's Beyond Smoke and Mirrors: Mexican Immigration in an Era of Economic Integration (2002).
The United States’ enforcement-only efforts have failed to stem the flow of illegal immigration, but they have yielded three perverse and unintended consequences.
First, enforcement efforts in urban areas have diverted the inflow to more remote desert regions where the rate of interception has actually dropped. Because of more sophisticated smuggling operations through these more remote regions, an individual attempting to sneak into the country is actually more likely to succeed today than when border enforcement was more lax in the early 1990s.
Second, immigrants entering the country illegally are more likely to die in the attempt. The death rate of migrants crossing the border with Mexico tripled during the 1990s. In recent years, 300 to 400 people have died horrible deaths along the border from heat stroke and dehydration. The death toll during the past decade has reached 3,500. Unclaimed and unnamed bodies have accumulated in morgues and makeshift refrigerator trucks along the border.
Finally, illegal immigrants entering the country today stay longer than before the United States began more aggressive enforcement at the border. Because the United States’ enforcement-only efforts have raised the cost and risk of crossing the border, those who successfully enter are more inclined to stay. As a result, the average length of stay for a Mexican entering the United States has doubled, from 2.6 years in the 1980s to more than five years currently.
The United States’ current policy has perversely interrupted what had been an established circular pattern of migration from Mexico to the United States. From the mid-1960s to the mid-1980s, during a time of relatively relaxed border enforcement, an estimated 80% of Mexicans who entered the United States illegally eventually returned to Mexico.