Community Spread in Massachusetts – Part II

What a day, as we learn Trump tested positive for the coronavirus. No further comment is necessary on that. But here’s a trivia question for you. Over the two week period ending September 26, what Massachusetts community had the highest per capita Covid testing rate? Stop. Before you read on, think about it. Is it Chelsea, or Everett, or Lowell, or another one of the hot spot communities in Massachusetts? Is it Boston, because of the many medical centers located there? No.

As Table 1 shows, the big winner is Williamstown, home to Williams College.  More than 4% of Williamstown’s population is being tested each day for coronavirus.  Of course, this figure is somewhat distorted, as many of those tested are presumably students who are not included in Williamstown’s stated population.  But even if one assumes that all of Williams College’s students (about 2,000) were back on campus, the per capita testing rate is astounding.

And there was even more testing being done in Williamstown for the two weeks ending September 19th, as it had the largest dropoff in testing from week to week.  In all, nine of the top ten per capita testing communities are home to college and universities. And even Somerville’s inclusion might partially reflect testing associated with Tufts. (In the original version of this post, I had stated that Dudley was a outlier, because I didn’t realize that it is home to Nichols College, which has done extensive testing.  Thanks to Jen for pointing out the error).

One technical point. It is possible, although unlikely, that there are communities in Massachusetts with higher testing rates than shown here. Why? I am using population estimates that are embedded in the weekly report itself (it can be derived from the daily incident rate and the number of cases). But if there are fewer than five cases, the state suppresses the exact number, so I can’t derive a population estimate. In fact, of the 351 communities in Massachusetts covered in the report, I can’t calculate a population for over half. I could try to pull population estimates from other sources and integrate them into this analysis, but I think it highly unlikely this will add any community to the top ten list (and I’m lazy).

One other point related to the blog itself. As I noted when I first started, I’ve never blogged before. I’m learning as I go. And I noticed yesterday’s post via email, on a tablet, or on cell phone has strange formatting or the numbers weren’t visible through the colors. I am trying to learn how better to format the posts, but for now, if you flip your device to landscape mode, the posts become more readable (and I’ve bolded the numbers within colored cells).