Chris Kavanagh
3 min readFeb 28, 2018


Citing the ‘Crime Prevention Research Center’ as a reliable resource is extremely problematic. Despite the intentionally innocuous name it is not some neutral research organisation but the guns right advocacy organisation of John Lotts author of ‘More Guns, Less Crime’, ‘The Bias Against Guns’, and ‘Freedomnomics’. The titles give some hint as to the author’s biases, as does his position as a columnist at Fox news.

As someone who cares about statistics and their misuse, I would have hoped you would recognise the problems in how sources like the CPRC misrepresent the data. Charles Petzold many years ago provided an excellent summary of why the CRPC data, that you endorse here, is entirely misleading.

As he explains, the problems relate to a poor understanding of statistical significance:

The primary purpose of statistics is to help us understand various phenomena of the real world and possibly to predict what might happen in the future. How meaningful is the fact that Finland tops the chart with a rate of 0.369 mass shootings per million of population over a five-year period? Does it tell us anything significant about Finland? Does it mean that Finland is the mass shooting capitol of the world? How could it, with only two mass-shooting incidences in five years? Does it mean that Finland will continue to have two mass shootings every five years? Not necessarily. The numbers are too small to tell us anything.

Tiny numbers do not make good statistics. Yet, all the countries in this table (except one) experienced just three mass shootings or fewer. These are very tiny numbers and their statistical significance is pretty much negligible.

He then runs a bunch of models and examines probability distributions against the observed data, and his conclusion:

To get meaningful information from data concerning mass shootings, it is necessary to be aware of statistical fluctuations that result from an insufficient numbers of incidents. Once that is done, it becomes obvious that the rate of mass shootings in the United States is significantly higher than the other OECD countries.

I’d advise anyone interested to read his comprehensive analysis.

I realise your larger argument is that we should be comparing the US against non-OECD countries but that sounds like a bit of a deflection. No-one is denying that the US is likely to suffer from less gun violence than Colombia. The point with comparing the US with other OECD countries is that have comparable levels of economic development and strength of governance and thus it is more meaningful that the US is an outlier amongst this group. That the US is safer than Jamaica is not really in dispute and there is a lot more confounding such comparisons. Adding in other less similar country comparisons also does not alter the demonstrably fact that the US in an outlier when compared using meaningful statistical comparisons with other similar countries.

Whether someone is pro-, anti-, or ambivalent about the situation in the US should be irrelevant to recognising the patterns appropriate statistical analysis reveals.



Chris Kavanagh

I’m a ‘cognitive anthropologist’ working for Oxford University but living in Japan. Interested in the psychology of religion, critical thinking and politics.