The National Rifle Association (NRA) convention in Dallas, Texas, May 5, 2018. (Lucas Jackson/Reuters)

Fake Einstein once said it’s the definition of insanity to do the same thing over and over again and expect a different result. But what’s it called when you do the same thing over and over again for the purpose of getting the same result, knowing the mainstream media will let you pretend you’ve done something new and exciting each time? That’s the question raised by a New York Times piece entitled “That Assault Weapon Ban? It Really Did Work.”

A couple years ago a chart by the researcher Louis Klarevas made the rounds showing that “gun massacres” fell during the assault-weapon ban that was in effect from 1994 to 2004. I wrote at the time:

[Klarevas counts] incidents in which six or more people are killed. . . . The pattern here is real; it shows up in the data set compiled by Mother Jones — which puts the fatality cutoff at four, includes only incidents that occur in public, and excludes gang activity — as well. As you can see in a chart made by Alan Reynolds at Cato, while the ban years included a rash of school shootings including Columbine, they also included some unusually calm years in the early to mid 2000s. It’s worth noting, though, that if you look at all incidents including four or more fatalities, the pattern is no longer evident.

So: Yes, there was a dip in mass shootings, at least under certain definitions of that term, during the ban. The ban years were especially peaceful mass-shooting-wise when compared with the horrific rise we’ve seen lately. But no, that doesn’t mean the ban caused the dip or that its expiration caused the recent rise — and there are good reasons to doubt it.

Don’t forget, for example, that the ban only stopped new guns and magazines from entering the market; it did nothing to reduce the supply of used copies. After all, Columbine happened during the ban, and in that case a minor used a “banned” weapon he was able to procure anyway. Even if you think gun bans work, a ten-year pause on new sales of certain specific types of weapons is not very likely to have a measurable impact, especially on such a statistically rare and erratic crime as mass shootings. Also important is that the features distinguishing “assault weapons” from ordinary hunting rifles are essentially cosmetic, and that handguns, not rifles of any kind, are the type of weapon most frequently used in mass shootings.

That didn’t stop Joe Biden from claiming the ban worked earlier this summer in the New York Times, though, and further claiming “multiple analyses” backed him up — pointing to another study that did more or less the same analysis on a different data set.

And now we have that New York Times piece touting yet another piece of research:

Recent mass shootings have revived demands for meaningful gun control. But many opponents of a renewed federal ban on assault weapons, led by the National Rifle Association, say the earlier ban, from 1994 to 2004, made no difference. Our new research shows otherwise. We found that public mass shootings — which we defined as incidents in which a gunman killed at least six people in public — dropped during the decade of the federal ban. Yet, in the 15 years since the ban ended, the trajectory of gun massacres has been sharply upward, largely tracking the growth in ownership of military-style weapons and high-capacity magazines. Using the Mother Jones mass shooting database, we identified the number of gun massacres over a 35-year period. (And following the F.B.I.’s approach, we excluded crimes of armed robbery and gang or domestic violence in evaluating public active shooter incidents.) Compared with the decade before its adoption, the federal assault weapon ban in effect from September 1994 through 2004 was associated with a 25 percent drop in gun massacres (from eight to six) and a 40 percent drop in fatalities (from 81 to 49).

Gee. You don’t say.