The 2009 homicide data for Chihuahua has been updated

on Oct 20, 2010
As I described in this post, the reported number of homicides[1] in Chihuahua during 2009 turned out to be incomplete. Guess what? The SNSP just released [xls file] an updated version of the homicide data, and Chihuahua went from having 2,523 homicides to 3,156. My estimate was 3,256, so I came pretty close. And the homicide rate for the whole country was 15, exactly what I predicted.

Score one for linear regression on World Statistics Day. Now we'll just have to wait until the INEGI releases it's numbers based on death certificates to see what the real number of homicide deaths was (3,600?).
Since the SNSP conveniently forgot to mention that the first numbers it released in 2008 and 2009 were incomplete, and nothing like this had ever happened before, the official homicide statistics are turning into a real mess of incompatible numbers. For example, this report from the ICESI uses the original 2008 data, and this study by Mexico Evalúa and this story in The Economist use the original data from 2009.

P.S. Here's the code

[1] More accurately the number of police reports, which may contain more than one victim

OpenHeatMap of the Drug War in Mexico

OpenHeatMap is an open-source tool that lets you turn a spreadsheets into a maps. It is very user-friendly if you have lots of data because it allows you to zoom into the map, and if you're like me and can never remember the exact location of important cities, when you hover your mouse over a region it shows you its name and the exact value you assigned it.

But best of all Pete Warden just updated OpenHeatMap with maps of Mexico at the municipality level. I decided to take advantage of this and built a HeatMap/Choropleth of the murder rate in Mexico for the last three years (the drug war started December 2006).

The spreadsheet I used to build the maps looks like this:

mex_muni_code value time
01001 3.1 2006
01001 3.9 2007
01001 5.7 2008
01002 2.4 2006
01002 2.4 2007

The mex_muni_code column corresponds to the combined state and municipality codes, the value column is the homicide rate, and time is an optional column if you want the map to have a slider so you can compare homicide rates over time. Once the spreadsheet is ready all you have to do it is upload it and you're set to go.