Well, I have to say that you are uniformed on the law. Any employment, no matter what term with a contract, requires full benefits. I know that personally as well as what the law says.
Your first post is confusing. You mention kids making 60 pesos a day as a construction worker. Are they kids? Albaniles are construction workers. Under them are peones, or unskilled workers. You say that albaniles make 250 a day. That's actually a working wage in Mexico which entitles the worker to a low-interest home loan at 6% guaranteed and payments as low as 500 pesos a month. Many of our family and friends fall into that wage category and do quite well; house, used car, kids are all in school.
Your tone to me is condescending. I've stated my work many times and I will again. I am a teacher, I contract out to the education department both on state levels as well as federal. I have worked in many rural settings including those with indigenous populations. I know the benefits that families receive including free milk (minimum 100 people and a formal petition), the program Oportunidades which has now been changed to Prospera which provides large cash incentives to rural families to keep their kids in school, so much so that many families have stopped working.
(SEDESOL Pensión para Adultos Mayores, Seguro de Vida para Jefas de Familia, Estancias Infantiles, Empleo Temporal, Jornaleros Agrícolas, Liconsa, Diconsa, Oportunidades, se reforzará la atención de la población)
I know Kino and have worked in Guaymas, Mexicali, Tecate, Rio Colorado, Ensenada, Rosarito, Tijuana, and many other cities and towns in between. Your vision of Mexico is one of corruption and poverty while mine is one of economic growth and development that other American countries are not seeing.
The article above makes one very important point, "almost 60 percent of Mexico's workforce was in the informal economy", a very true and sad statement but one that is driven almost always by choice.
If what you say is true, and I were an albanil making sixty pesos a day, I would get the heck out of Kino, sounds like a not so nice place based on that. The guy would be better off washing windshields on a corner than doing back-breaking work for 60 pesos a day. The rest of northern Mexico is a strong and vibrant engine where good-paying jobs are on the rise and people are on the move.