Why do Mexicos southern states lag behind the rest of the country?

Answer 1

The answer is as complex as answering "why does poverty exist", but the most logical theory states that, poverty is the result of high inequalities inherited since the colonial days (1521-1821), when an elite of criollo people agglomerated most of the means of production, leaving the rest of the population to serve them, often in poor conditions. As a large segment of the population (up to 32% on all three states) was composed by indigenous people, nobody within the rising capitalist class saw the necessity to improve their health, education or living conditions, much akin to the African-American population on the southern states well into the 20th century.

Although the Mexican Revolution (1910-1921) tried to solve many of these problems, the reality is that nothing changed, as means of production often ended on the wrong hands: large tracts of productive land were given to uneducated, illiterate people who didn't know how to tend rich coffee, sugar cane and fruit plantations, switching them into subsistence farming "ejidos", where maize and beans were cultivated.