Is femicide increasing in Mexico? Gender specific rates for Mexican States between 2005 and 2010 in Mexico

State Level Change in the ratio of Female-to-Male homicide between 2005 and 2010

J. Creechan

October 2, 2012

The following table and two scatterplots use INEGI homicide data from 2005 and 2010 for each State (and DF) to analyze how the proportion of female murders has changed. Specific gender homicide rates were calculated for both 2005 and 2010: that is, the female homicide rates were calculated by the formula SpecificFemaleHomicideRate= (number of females murdered/number of females in State)*100,000 and the male rates were calculated by the formula SpecificMaleHomicideRate=(number of males murdered/number of males in the State)*100,000.

Once the gender specific rates were calculated, a ratio of female to male homicides was calculated. This value is listed in the table as RatioSpCrYR_MH where YR is either 2005 or 2010.

The first table contains the ratio of female to male homicides for each year (2005, 2010). Column one lists states in ascending order from the largest drop in how much females contribute to the number of murders in a State to those States with the highest increase in the proportion of female homicides after 2005. For example, the first row is for Aguascalientes and it indicates that it dropped from a high of 36.4% female homicides in 2005 to a relative proportion of 14.6% in 2010. This means that the ratio of female to male homicides in Aguascalientes had dropped by 22 percentage points in Aguascalientes in 5 years.

The biggest increases in the ratio of female to male homicides from 2005 to 2010 is seen in Campeche where the percentage of female homicides (calculated using specific gender rates) escalated by a factor of 3: it changed from 6.7% in 2005 to 22.7% in the Campeche homicide data for 2010.

Gender specific rates were used to compute these ratios since there are large gender population differences in many Mexican States and there are more females than males. That means that the ratios used in this analysis are conservative estimates that generate a smaller proportionate rate for females than when the overall population is used. Basically, the denominator for females is larger and generates a larger gender homcide rate and the denominator for males is smaller and results in a larger rate. Overall, this leads to a more conservative ratio of female to male homicides than if a general (total population) figure had been used to calculate gender rates. It is also more conservative than if the absolute number of homicides within each State is used to compute a ratio.

The table is colour coded to indicate direction (UP-DOWN) and degree (magnitute) of change in the ratio of female to male homicides to male homicides (based on gender specific rates). The turquoise blue States (Aguascalientes, Colima, Tlaxcala and Zacatecas) showed the largest drop in female contribution to the homicide ratio between 2005 and 2010. Overall, there were only 25% (8 of 32) jurisdictions where the female contribution escalated disproportionately. In ascending order these are Nayarit, Chiapas, Michoacan, Tabasco, San Luis Potosi, Baja California Sur, Hidalgo and Campeche. All Mexican States have seen escalating homicide rates, but this list is interesting because with the exception of Michoacan are NOT the States considered to be major battlegrounds in Felipe Calderón’s war. It is true that San Luis Potosi and Hidalgo recently escalated into major plazas because of expansion or internal battles involving Los Zetas, but the fact is that most of the escalation has in 2011 and 2012 and is not represented by this data.

Perhaps many will be surprised to see which States experienced either a drop in the proportion of female homicides or experience little change. Among these are the traditional drug plazas such as Sinaloa, Tamaulipas, and Chihuahua. Overall, it appears that there has been little change in the female to male homicide ratio in those areas of Mexico where the drug wars have been bloodiest.

NOTE: RATIOSPCr05-MH is the ratio of gender specific crime rates for 2005 (Mujeres a Hombres), and RATIOSPCr10-MH is the ratio of gender specific crime rates for 2005 (Mujeres a Hombres). The value in each cell is computed using the gender specific homicide rates of Mujeres and Hombres for that State in that year). An alternative would have been to simply compute a ratio of the homicide counts for males and females in each State for each year. These figures were computed and produce no differences in the overall pattern. Source: INEGI

The data in the table has been plotted in scatterplots in two different sequential orders, and these scatterplots of the changes provide a graphic representation of how female and male homicide rates have changed relative to each other in the census period 2005 to 2010. The changes in these years are primarily related to Felipe Calderón’s escalation of the drug war. Ideally, the same analysis should have focused on his sexenio period (2006 to 2012), but the fact is that there are no homicide figures for 2012 and in fact the only years that the population estimates are reasonably accurate are the census years.

The following scatterplot uses these proportions and plots them against each other. The blue line (top line on the left) in the graph is the data series for 2005, and the red line (bottom line on the left side) is from 2010. The scatterplot also includes drop lines (gray) indicating the size of the change (drop) within each State, and an increase line (light red) indicating how female homicides have contributed a greater proportion of homcides. It is obvious that there is a part of the scatterplot on the right hand side there the two census years are indistinguishable from each other. The States of Sinaloa, Vera Cruz and Queretaro are essentially unchanged.

I also examined the correlation coefficient between “change in the overall homicide rate” (for each State) and the “ratio of female to male homicides” within each State and it is effectively zero (r=-.01). Basically, this means that there is no relationship between the increase in the overall number of homicides and the relative proportion of female homicides.

The ratio of female to male homicides in the scatterplot presents the data for each State in sequential order from largest decline to largest increase in female-to-male ratios between 2010 and 2005 

The ratio of female to male homicides in the scatterplot presents the data for each State in sequential order from the lowest contribution value for females in the female-to-male ratios in 2005. The pink blocks are States with increases and the green blocks represent a drop in the level female homicide contributes to the ratio.