Quarantine fatigue thins fat-tailed coronavirus impacts in U.S. cities by making epidemics inevitable

We use detailed location data to show that contact rates in most U.S. cities are fat tailed, suggesting that the fat tails previously documented in a small number of case studies are widespread. We integrate these results into a stochastic compartmental model to show that COVID-19 impacts were also fat tailed for many large U.S. cities for several weeks in the spring and summer. Due to thresholds in epidemiological dynamics, fat-tailed impacts would have been more prevalent if not for the gradual increase in contact rates throughout the summer that made an outbreak more certain.