Agreed.
Er. High intracountry crime variance does not refute (or even address) intercountry crime differentials, or their statistical significance.
These are based on statistical surveys. The underlying sample sizes are a great deal larger.
Actually, in 1988 (prior to fall of the Berlin Wall and its associated spike in East European migration), the largest discrepancy was a great deal larger (more like 70%).
You cannot conclude this without knowing the sample sizes of the underlying survey (and therefore their confidence intervals).
For the casual reader: my impression of the data conflicts with Blake. (I think the US usually has higher rates of violent crime and much higher murder rates (props to jshore for digging up that data), relative to other first world countries. Nonviolent crime is more difficult to characterize (translation: I’m not sure.)). I, however, have substantiated my remarks with an actual dataset.
I concede that my report is not conclusive: the evidence is middling (though not weak, I’d argue). Typically, telephone surveys have a precision of around 3%. So differentials of 6% or more are likely to be significant (assuming independently distributed measurement errors). Yes the actual math is more complicated and would require sample variances and probably an assumption of normality. See variance, rule 4. So Britain had practically the same violent crime as the US in 1995, while that of Canada, Finland and the Netherlands was lower than the US.
It would be better though if a had a more recent data point than 1995. Also, inquiring minds might wonder about France, Germany, Italy, Australia and Japan.
FULL DISCLOSURE: I see that my “violent crime index” consists of the simple sum of 3 crime rate categories: robbery, sexual offences and “assault and threat”. I then normalized that summed rate against the US.
I welcome links to more considered investigations.