I thought so too until I read the last 3 paragraphs. "Those numbers check out" is totally valid. But concluding with the relevance of the measure of gun harm is an observation about reality, not Statistics, which is debatable, but has no relevance to what was previously mentioned.
We haven't yet defined the goals. Unless "Minimum amount of gun-related deaths" is the goal (clearly, it isn't that simple in this country), in which case his highlighted claim is definitely false - we don't know much about effective metrics. Are the psychological effects of a mass shooting similar to a snowball effect? Maybe in the long run? There's a lot more to research before saying 'insignificant', especially if you don't describe the model.
One more thought: could you define 'mass shooting'? Usually the media is responsible for that definition, whereas a random murder isn't called that.
The conclusion about the relevance of the measure of gun harm seems to me the "mass shootings in 1 year does not necessarily signal a significant change from the past 30 years" part. It means that discussions along the line of "Why the change?", or "How can we go back to the way it was before?" are premature, though it does not say anything at all about discussions along the line of "How do we reduce mass shootings?".
Mother Jones probably did a pretty decent job of defining 'mass shooting', I assume they errored on the side of inclusion (I only recall 2 this year). The authors analysis seems to make it pretty clear it is only considering that definition.
I'm really not reading this as an attack on discussions of gun violence in general, as it seems you are.
We haven't yet defined the goals. Unless "Minimum amount of gun-related deaths" is the goal (clearly, it isn't that simple in this country), in which case his highlighted claim is definitely false - we don't know much about effective metrics. Are the psychological effects of a mass shooting similar to a snowball effect? Maybe in the long run? There's a lot more to research before saying 'insignificant', especially if you don't describe the model.
One more thought: could you define 'mass shooting'? Usually the media is responsible for that definition, whereas a random murder isn't called that.