When percentages mislead

on Jan 31, 2011

According to security spokesman Alejandro Poiré violence in Mexico is a regional phenomenon since 85 municipalities concentrate 70% of drug related homicides. While it is certainly correct to say that not all of México has suffered from the drug war, it is misleading to present the percentage of total homicides concentrated in a few municipalities as evidence. Municipalities have different populations and furthermore drug related homicides increased from 2,826 in 2007 to 15,273 in 2010 which makes it even harder to interpret the percentages.

A much better way to show the the concentration of violence is to calculate the percentage of the Mexican population living at or above a homicide rate. Since it is much more trustworthy than the drug related homicide database Poiré uses, I decided to use the recently released mortality database as my source.

Number of people living in a municipality with a homicide rate above 50:

2006 - 1,100,000
2007 - 850,000
2008 - 5,800,000
2009 - 9,100,000

Number of people living in a municipality with a homicide rate above 10:

2006 - 33,500,000
2007 - 26,500,000
2008 - 42,300,000
2009 - 54,900,000

While it is certainly true that violence is concentrated, the number of people suffering its effects has increased greatly.

Homicides in Mexico 2006-2009

on Jan 27, 2011
Just today the Mexican government released to the public the mortality database for 2009, and as you can see from the chart Mexico has suffered from a steep rise in homicides from 2008 onward and very likely reached the highest violence rate in recent history last year. Since the Mexican government also recently made available a database of homicides presumably linked with the drug war we can divide homicides into those related to the drug war an those that are not: