Overall: Charts that estimate collective risk that large events will have one (or more) COVID-19 positive individuals.
Charts that provide estimates of the probability (i.e., the 'risk') that one or more individuals who are COVID-19 positive are at an event of size n (x-axis). The y-axis makes different assumptions about the number of circulating cases in the USA (I). The main chart uses lines of constant 'risk', i.e., 1%, 2%, 10%, 50% and 90% for combinations of n and I. Two scenarios are then considered (I=2,000 and I=20,000) such that the risk for events of different sizes n can be read off the corresponding horizontal lines.
Key note: the chart assumes homogeneous incidence. In reality, risk is heterogeneous, though significant uncertainty exists on local prevalence of COVID-19 as of 3/10/2020.
Joshua S. Weitz, jsweitz@gatech.edu, http://ecotheory.biology.gatech.edu
Figures here: https://figshare.com/articles/COVID-19_Event_Risk_Assessment_Planner/11965533
Updated: April 18, 2020 Using https://covidtracking.com/data/us-daily Assuming Last 2 week positives as estimate of 'Circulating Cases' and then multiplying by 5x and 20x to get the alternative scenarios
NOTE: THE REASONABLE UNCERTAINTY IN THIS CALCULATION EXCEEDS THE SCENARIOS SHOWN HERE