Yes, there are. "In 2010 the average of Mexico’s three region-based minimum wages is around U.S. $4.50 per day." - US Department of State (http://www.state.gov/r/pa/ei/bgn/35749.htm)
That's $4.50 a day (Or $1642.50 for an annual salary, if you worked all 365 days in the year). That's the average. I don't know about you, but I'd be hard-pressed to support myself on $4.50 an hour. Now what if I had to support an entire family on that? Say you have a family of four. At $4.50 per day, each person gets $1.13 to live off of per day, or $410.63 per year. How much money to you need to live on each day? Could you support yourself and your family with such wages?
So the answer is no, there is not sustainable employment for the average Mexican citizen in Mexico.
South of Mexico are Guatemala and Belize. People who live in Guatemala and Belize are running out of those countries, through Mexico, to get to America, so why would a Mexican be better off going that way?He'll have to move from his village, but he was prepared to do that anyway. And if he has enough money to pay the coyotes, he has enough to buy food for his family on the journey south.
You're hungry, you have no money (whether or not you have a job), and your children need to eat tomorrow.