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Business Closures, Stay-at-Home Restrictions, and COVID-19 Testing Outcomes in New York City


The positivity rate reached a maximum of 71% on March 28 and declined steadily in the next 2 months. By May 31, only 4% of tests had a positive outcome. The business activity and stay-at-home indices were near their prepandemic value of 100 until about the middle of March. At that time, the business activity index rapidly declined; on April 16 it reached a low of 22.9 and stayed below 50 through May 31. In contrast, the stay-at-home index increased rapidly, reaching a peak of 206.6 on April 8; between mid-April and May 31, it hovered around 175.


Citywide trends in the positivity rate for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and business activity and stay-at-home indices, New York City, March 3–May 31, 2020. The positivity rate gives the percentage of daily tests that had a positive result; the business activity index gives the number of visitors to points of interest (such places as stores, restaurants, parks, hospitals, or museums) in a zip code; and the stay-at-home index counts the number of smartphone devices that did not leave their home location. Both indices are averaged across zip codes (weighted by population), are lagged 3 to 7 days before the day of the test, and are normalized to equal 100 in the prepandemic period of February 4 through 6.

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Page last reviewed: September 17, 2020