> And in 2022 we're on track for somewhere between 40 and 48, precisely in line with prior years. A single outlier year does not a trend make.

I didn't claim a trend in SF homicides, I was responding to your claim that 2021 homicides are at the same level as 2018.

> Until 2016, when it began dropping again, and then it jumped up a ton in 2020 but we don't really have data yet to know if that was a fluke or not. (it really looks like the 2014 thing was just regression to the mean).

The post-2020 "spike" (is it a spike if it hasn't come back down abruptly/dramatically?) has persisted for 2 years. Researchers insist the ~2014 surge was not a fluke or a blip, and the 2020-2022 "spike" is much more dramatic.

> “These aren’t flukes or blips, this is a real increase,” he said. “It was worrisome. We need to figure out why it happened.”

https://www.theguardian.com/us-news/2016/may/13/ferguson-eff...

And researchers disagree that the 2014 surge was merely a regression to the mean. From https://www.theguardian.com/us-news/2016/may/13/ferguson-eff...:

> While it’s not clear what drove the increases, he said, he believes there is some connection between high-profile protests over police killings of unarmed black men, a further breakdown in black citizens’ trust of the police, and an increase in community violence.

> “The only explanation that gets the timing right is a version of the Ferguson effect,” Rosenfeld said. Now, he said, that’s his “leading hypothesis”.

> “That led me to conclude, preliminarily, that something like a Ferguson effect was responsible for the increase,” he said.

From https://www.vox.com/22360290/black-lives-matter-protest-crim...:

> Campbell’s research also indicates that these protests correlate with a 10 percent increase in murders in the areas that saw BLM protests. That means from 2014 to 2019, there were somewhere between 1,000 and 6,000 more homicides than would have been expected if places with protests were on the same trend as places that did not have protests. Campbell’s research does not include the effects of last summer’s historic wave of protests because researchers do not yet have all the relevant data. ... His research on homicides aligns with other evidence. Omar Wasow, a professor at Princeton University who has done seminal research on the effect of protests, told Vox that the results are “entirely plausible” and “not surprising,” considering existing protest research.

Note also the aforementioned paper (https://www.nber.org/system/files/working_papers/w27324/w273...) from famed Harvard economist Roland Fryer and Tanaya Devi which found an increase in violent crime rate in cities that experienced a prominent BLM shooting (and subsequent protests), resulting in an additional 900 homicides and 34,000 excess felonies across two years. They suggest that this was caused by changes in the quantity of policing.

We'll have to wait for the 2020 and 2021 data to understand that spike; however, it seems really unlikely that prior to 2020 homicides were driven by anti-policing protests, but afterward it's merely a coincidence that the largest homicide surge immediately followed the largest bout of anti-policing protests.