A simple method to quantify country-specific effects of COVID-19 containment measures

Morten Gram Pedersen; Matteo Meneghini

Most countries and regions initially had similar growth rates of 0.2-0.3/day (Fig. 2) , corresponding to a doubling time of ∼2.5-3.5 days. However, growth in New York City (N.Y.C.) was much faster with a doubling time of ∼1.4 days. After the date-of-change all regions lowered the growth rate significantly (p < 0.001). We estimated that the growth rate in Austria, Switzerland, and British Columbia (B.C.) is practically zero, i.e., the basic reproduction number R 0 ≈ 1, whereas New South Wales (N.S.W.) have statistically significant negative growth rate (p = 0.02). Italy, Germany, and N.Y.C. have growth rates of ∼0.03-0.06/day, i.e. doubling times of 11-22 days. In a more detailed analysis with two dates-of-change (not shown here) we have estimated that Italy more recently have lowered the growth rate to ∼0/day following closure of job activities deemed not strictly necessary. France, Spain and the UK still have growth rates of 0.08-0.11/day (doubling times 6.5-8.5 days).