Mexican farm laborers earned less than three dollars a day in 2013 in Mexico, according to information released last week by the National Institute of Statistics and Geography (INEGI by its Spanish acronym.)

Farmworkers’ wages do not represent any more than 1.5 percent of the earnings of those who work in large corporations in Mexico, according to INEGI.

In fact, the gap between the two sectors is so wide that a corporate executive only needs to work 5.6 days to earn what an agricultural worker earns in a year.

Seventy percent of the field workers earn less than $2 US per day. Ninety-five percent do not enjoy any health or social security benefits. That puts Mexican field workers after China as the most exploited in the world, according to the World Bank.

With conditions like these, it is no wonder that the United States federal minimum wage of $7.25 per hour is attractive. The National Council on Population indicated that 400,000 people immigrate to the United States per year, many as undocumented workers. While many go to urban centers to work in restaurants and sweatshops, others continue working on farms all over the United States.

Of all farmworkers in the United States, 75 percent were born in Mexico, 53 percent of farmworkers in the United are undocumented (without legal authorization,) 25 percent are United States citizens, and 21 percent are legal permanent residents. According to US Department of Labor’s Bureau of Labor Statistics, farm work generally pays more than $9 per hour, but due to colder winters, the work is usually seasonal, strenuous, and dangerous. And since more than half of the workers don't have papers, growers can get away with paying less than $9.

Immigration to the United States has markedly increased since the 1994 passing of NAFTA, a free trade agreement that has driven over two million Mexican farmers out of business. And the downward pressure on post-NAFTA real wages for farmers in Mexico will only serve to drive migration numbers up even higher.