COVID Tracking Project vs. JHU
As of May 31, there were 5,845 more deaths reported by JHU than by COVID Tracking Project. The last time JHU's death toll was not higher than that of COVID Tracking Project was March 15, when the former exceeded the latter by just 6 deaths. March 29 was the last time JHU's death toll exceeded that of COVID Tracking Project by less than 1,000 deaths (in that case, the difference between the two was 991 deaths).
The Pearson correlation between the number of deaths reported by COVID Tracking Project and JHU was 0.9996166.
COVID Tracking Project vs. NYT
As of May 31, there were 5,845 more deaths in the US reported by the NYT than by COVID Tracking Project, and the last time that COVID Tracking Project reported more deaths nationally than NYT (as well as the last time NYT did not report more deaths than COVID Tracking Project) was over two months earlier on March 17, when COVID Tracking Project reported 3 more deaths nationally than NYT. Every day since (and including) April 5, the NYT's death count has exceeded that of COVID Tracking Project by at least 1,000 (meaning April 4, when NYT's death count exceeded COVID Tracking Project's by 979 deaths, is the last time that NYT's lead over COVID Tracking Project in this regard was less than 1,000 deaths). The last date when the NYT did not report at least 5,000 more deaths nationally than did COVID Tracking Project was May 11, when NYT reported 4,980 more deaths than COVID Tracking Project. Every day from May 12 to May 31 inclusive, the NYT has reported between 5,000 and 6,000 more deaths than COVID Tracking Project.
The Pearson correlation between the number of deaths reported by COVID Tracking Project and NYT was 0.9997858.
COVID Tracking Project vs. USAFacts
As of May 31, there were 4,489 more deaths in the US reported by USAFacts than by COVID Tracking Project, and the last time that USAFacts did not report more deaths nationally than COVID Tracking Project was March 17, when the two trackers reported an identical number of deaths. (The last time COVID Tracking Project reported more deaths than USAFacts was two days earlier, March 15, when it reported 5 more deaths than USAFacts.) As with the NYT (as noted just above), USAFacts' death count has exceeded that of COVID Tracking Project by over 1,000 every day starting April 5. The last date when this excess was less than 1,000 was April 4, when USAFacts reported 906 more deaths than COVID Tracking Project.
The Pearson correlation between the number of deaths reported by COVID Tracking Project and USAFacts was 0.9998093.
NYT vs. USAFacts
As of May 31, there were 778 more deaths in the US reported by NYT than by USAFacts, and the last time that NYT did not report more deaths nationally than USAFacts (as well as the last time USAFacts reported more deaths than NYT) was April 10, when USAFacts reported 133 more deaths than NYT.
The Pearson correlation between the number of deaths reported by NYT and USAFacts was 0.9999855.
NYT vs. JHU
As of May 31, the NYT and JHU trackers were reporting exactly the same number of deaths in the US. These two trackers were relatively close to each other during the month of May: for example, they were less than 100 deaths apart from May 11 to May 31 inclusive, and they have been less than 1,000 deaths apart from April 19 to May 31 inclusive.
The Pearson correlation between the number of deaths reported by NYT and JHU was 0.9999111.
USAFacts vs. JHU
As of May 31, JHU was reporting 778 more deaths in the US than USAFacts. This was part of a clear long-term pattern: from March 17 to May 31 inclusive, JHU reported more deaths than USAFacts.
The Pearson correlation between the number of deaths reported by USAFacts and JHU was 0.9998943.
Discussion
This study presents comparisons of the number of total US cases and deaths reported by the NYT, JHU, USAFacts, and COVID Tracking Project. Very strong correlations were consistently found between the values reported by each of the trackers, indicating a high level of agreement. Nevertheless, there were some conspicuous discrepancies between some of the trackers, with the NYT reporting consistently more cases than COVID Tracking Project or USAFacts (and to a lesser extent JHU), beginning in late March/early April. The lead NYT's reported number of cases has over those reported by COVID Tracking Project and USAFacts has increased steadily since early April, and the magnitude of NYT's lead over COVID Tracking Project in this regard has consistently been roughly the same as that of NYT's lead over USAFacts. NYT's lead in number of reported cases over JHU has also been increasing steadily since early April, but at a significantly slower rate than has NYT's lead over COVID Tracking Project or USAFacts.
Starting around the same time, NYT began to report significantly more deaths than COVID Tracking Project nationally, and this number continued increasing steadily for about a month thereafter; it has since remained relatively flat. On April 10, NYT began reporting more deaths than USAFacts (though NYT's lead over USAFacts in the number of reported deaths has since continuously been much smaller than was its lead over COVID Tracking Project in this regard). NYT has reported almost exactly the same number of deaths as JHU since roughly early May. COVID Tracking Project has consistently reported fewer deaths than any of the other three trackers since March 15 or March 17, depending on the tracker. In general, the absolute difference in the number of deaths between any two of the four trackers included here has been relatively stable throughout the month of May.