Note: We have discontinued updating the chart below. We believe its potential for forecasting has been fulfilled.
The chart below is a comparison of the daily trajectory of total reported COVID-19 cases in Italy from February 24, 2020, through March 26, with that of Los Angeles County from March 18, 2020 through April 17. Italy was selected for comparison as an early and good example of a modern western society experiencing a COVID-19 outbreak.
By mid-March, L.A. County’s trajectory of COVID-19 cases had roughly aligned with that of Italy during late February. L.A. County’s daily rate of new cases, however, did not accelerate as quickly. A significant variable was that L.A. County (and California) chose not to delay issuing shelter-in-place orders as did Italy. Italy issued its nationwide shelter-in-place orders on March 10 after it had already recorded more than 10,000 cases and 600 deaths. By contrast, L.A. County issued its first shelter-in-place order on March 19 (just hours before the whole of California), when it recorded 231 cases and 1 death. As seen in the chart below, this ended up flattening L.A. County’s COVID-19 trajectory, causing it to quickly fall behind the unfortunate COVID-19 trajectory that occurred in Italy.