Seeking safety in Latin America

In Mexico City I am relieved to step out of the taxicab and into the street. Cabs are a major venue for robbery and kidnapping. In Rio de Janeiro I am relieved to step out of the street and into the taxicab. Cabs are relatively safe, but a twelve-year old street urchin might knife you in the gut for a dollar.

I've yet to find a good explanation for this difference in criminal method. Could it be that Mexican crime is more closely linked to the drug trade and especially the export of drugs to the U.S.? This increases the optimal size for a criminal gang and might cause robbery and mayhem to be better organized and more capital-intensive. Brazil also appears to have an especially bad educational system, which lowers the average criminal age but also diminishes the relevance of taxis.