Introduction

https://astralcodexten.substack.com/p/what-caused-the-2020-homicide-spike

In my review of San Fransicko, I mentioned that it was hard to separate the effect of San Francisco’s local policies from the general 2020 spike in homicides, which I attributed to the Black Lives Matter protests and subsequent police pullback.

The nationwide 2020 spike in homicides (source). The spike is small compared to the secular trend from the 1960s through 2000, but large by the standards of the past twenty years.

Several people in the comments questioned my attribution, saying that they’d read news articles saying the homicide spike was because of the pandemic, or that nobody knew what was causing the spike. I agree there are many articles like that, but I disagree with them. Here’s why: