There is an ugly and rather flawed battle waging on with regard to violent crime and illegal immigration. And, not surprisingly, Arizona is the battlefield, and fear is the ammunition.
Recently, the New York Times published a story claiming that illegal immigration in the Grand Canyon State has not resulted in a rise in crime, as certain interest groups would have us believe. To the contrary, the Times cited FBI crime statistics for the state showing that the rate of violent crime has dropped since 2000. The paper also quoted a number of researchers who not only debunk the modern myth of lawless illegals, but suggest that immigrants tend to have lower rates of criminality.
Adding to the state of confusion in the state of Arizona, blogger Tom Maguire then attempted to demonstrate that the reported decline in violent crime in Arizona during recent years is misleading -- a "statistical cover-up" of sorts. Maguire contends that the statewide figures obscure underlying violent crime increases outside the large metropolitan ares, especially small towns and rural communities at or near the Mexican border. Using more detailed FBI statistics for 2000 and 2008, Maguire reports that the violent crime rate did indeed drop in the state’s metropolitan areas, but rose sharply in non-metropolitan cities and counties where, supposedly, the illegal immigrants populate. His graphic is reproduced here:
In the couple of days since Maguire's post, the Net has been abuzz concerning this statistical revelation. Mark Hemingway, staff writer for the Washington Examiner, declaring Maguire as "one of the smartest guys in the blogosphere," called on the New York Times to issue a correction to its immigration story.
For the New York Times to print a retraction, or any sort of journalistic "mea culpa," would be just a bit premature. There are some other facts that entirely cast doubt on Maguire's analysis.
Maguire’s analysis is flawed -- more so than the Times piece he challenges. First, in examining only two different time points (2000 and 2008), a sharp increase could reflect an aberration at either end of the time interval. If one considers all the years between 2000 and 2008, a very different picture emerges. As shown in Figure 1 below, while the violent crime rate in non-metropolitan cities areas does appear to have increased steadily, the jump in non-metropolitan counties is only a reflection of a low crime level in 2000. Since 2001, however, the violent crime rate in non-metropolitan counties has changed very little.
Stepping the rate calculations back one more year to 1999 reveals even more about Maguire's erroneous conclusion. As shown in Figure 2 below, the 2000 rate for non-metropolitan counties was indeed an outlier. The trend in violent crime for these rural areas is essentially flat from 1999 through 2008.
But wait, there's more. The larger error in Maguire’s analysis comes from not seriously questioning or examining the substantial population drops between 2000 and 2008: from 304, 632 to 202,505 in non-metropolitan cities and from 314,634 to 271,734 in non-metropolitan counties. Such population changes are quite unusual, especially in the Sun Belt.
Figure 3 displays the estimated population counts used by the FBI for these two geographic composites for each of the years between 2000 and 2008. There clearly seems to have occurred between 2005 and 2006 some artificial shift in method/source of population estimation or definition of geography. And this impacted Maguire’s calculated crime rates, likely much more than did illegal immigration.
Given the break in population estimates between 2005 and 2006, any crime rate comparison that traverses this juncture is suspect. In terms of sub-state rate calculations for Arizona, only trends since 2006 are valid and interpretable. Even though three years of data are insufficient for concluding much in terms of trend, as shown in Figure 4, violent crime rates since 2006 do not suggest a consistent pattern of change.
While I applaud Tom Maguire for attempting to decompose aggregate state figures in search for the hidden story, he just didn't use all the tools and all the data available for the task at hand. More important, we should continue to engage in open policy debate about how the United States should deal with illegal immigrants. But maybe we should leave crime -- or at least fear -- out of the discussion when it doesn’t really belong.
Note: Figures were updated on June 23 to correct for a transcription error. There was no change, however, in the overall conclusion.
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