COVID-19 March 26, 2020

The leveling off of new infections in New York and New Jersey appears robust, although it is still not possible to rule out testing and reporting issues.  Since these two states together account for approximately half of all cases in the U.S., a change in their behavior impacts the U.S. totals.  In the total case figure below I have added a third best-fit line that uses only the last three days.  It shows a shallower slope than both the lines for all the data and the 10-day fit.  It's a flattening of the curve, and if it holds, it's good news.  The daily rate of change figure also shows a departure from the 10-day and total data best-fit lines.  Still, the daily rate is large--over 10,000 new cases every day.

Statistics can be deceiving.  Because NY and NJ dominate the total statistics, they can mask trends in other states.  Places like Florida, Texas, and Louisianna have exploding numbers.  Even in Connecticut, the numbers are growing, no doubt due to their proximity to New York and the delay in issuing "stay at home" orders from the Governor. The slow roll out of orders in nearby Pennsylvania is also likely behind the increase in that state.  None of these states' numbers are anywhere near NY yet, but given exponential growth they can get there very quickly.  There are many other states with similar patterns.  If immediate steps are not taken in these other areas, it is likely that a second surge of new infections will emerge in the next week. This will drive the growth curves back up.  Time will tell.

In the meantime, it looks like the grim 100,000 total has been delayed by perhaps a day thanks to the leveling of numbers in the NY area.  It still appears nearly unavoidable that we will get there.  The flattening of the curve even a little bit, however, is incredibly important for how things unfold in the long-term.  Whereas the 10-day best fit puts us at 1 million cases in the first few days of April, the three-day best fit pushes that milestone out a week further or more.  That's hugely important for the medical and health facilities, many of which are already at the breaking point.

One last thought for the day.  Don't forget that the actual number of infections is perhaps up to 10 times what's being reported.  That means we may very well be approaching 1M infections in the next day, not 100,000.