Robert VerBruggen of National Review Online questions Democratic presidential front-runner Joe Biden’s latest claim involving assault weapons.

Presidential candidate Joe Biden writes:

“Many police departments have reported an increase in criminals using assault weapons since 2004. And multiple analyses of the data around mass shootings provide evidence that, from 1994 to 2004, the years when assault weapons and high-capacity magazines were banned, there were fewer mass shootings — fewer deaths, fewer families needlessly destroyed.”

Somewhat perplexingly, the links on “multiple analyses” and “fewer mass shootings” actually go to the same study. …

… [T]he three most important facts about mass shootings are (A) they have historically been incredibly rare, with entire years passing without one sometimes; (B) they are contagious, with high-profile incidents inpiring copycats and competitors; and (C) they are incredibly variable in the number of fatalities, from a low bound of wherever the researcher chooses to set it (the study Biden cites uses four, not including the perpetrator) all the way up to 58 at Las Vegas. Trying to detect a pattern in data like this, and then attributing the pattern to a single law change that covered the entire country for a ten-year period, is madness.

The new study doesn’t add much to what we already know and is downright bizarre at times. For instance, the authors combine three different data sets of mass shootings, but instead of including all the incidents they found (to be as comprehensive as possible), they included only the incidents counted in all three databases. They also misuse the term “assault rifle,” which refers to a weapon capable of full-auto fire, indicating that not one of the nine authors and not one of the journal’s editors is all that familiar with firearms or the gun debate.