The total number of firearms purchased in Virginia increased 73 percent from 2006 to 2011. When state population increases are factored in, gun purchases per 100,000 Virginians rose 63 percent.
But the total number of gun-related violent crimes fell 24 percent over that period, and when adjusted for population, gun-related offenses dropped more than 27 percent, from 79 crimes per 100,000 in 2006 to 57 crimes in 2011.
. . .
“So while it’s difficult to make a direct causal link (that more guns are resulting in less crime), the numbers certainly present that that’s a real possibility,” [Virginia Commonwealth University professor Thomas R. Baker] added.
The opposite – that more guns are causing more crime – cannot be derived from the numbers, he said.
“It’s mathematically not possible, because the relationship is a negative relationship — they’re moving in the opposite direction,” Baker said. “So the only thing it could be is that more guns are causing less crime.”
The last quote is a little unfortunate — it is mathematically possible that guns increase crime and yet other factors worked to drive crime down on balance. (Similarly, the fact that illegitimacy rates have risen while crime rates have fallen doesn’t disprove the thesis that illegitimacy is one factor that causes crime.) But it is telling that these two numbers moved so dramatically in opposite directions.
Hat tip to Tim Lynch.