Evaluating the impact of international airline suspensions on the early global spread of COVID-19

Aniruddha Adiga; Srinivasan Venkatramanan; James Schlitt; Akhil Peddireddy; Allan Dickerman; Andrei Bura; Andrew Warren; Brian D Klahn; Chunhong Mao; Dawen Xie; Dustin Machi; Erin Raymond; Fanchao Meng; Golda Barrow; Henning Mortveit; Jiangzhuo Chen; Jim Walke; Joshua Goldstein; Mandy L Wilson; Mark Orr; Przemyslaw Porebski; Pyrros A Telionis; Richard Beckman; Stefan Hoops; Stephen Eubank; Young Yun Baek; Bryan Lewis; Madhav Marathe; Chris Barrett

The rise in the number of COVID-19 cases in China has led to series of suspensed operations by major airlines serving international traffic in and out of mainland China. Note that airline suspension can be complete or partial, and can affect the whole or part of an itinerary. Using the suspension data described earlier, we appropriately alter the flow volumes in the original air traffic network. To ensure that the effective distances on the air traffic network are comparable with and without interventions, we scale the flow volume in the latter with total outflow from origin in the former. Assuming that the total outflow from a country without airline suspensions is reflective of the country population size, normalizing the reduced flows with it could provide better estimates for P mn . Formally, if G is the original weighted flow network on which effective distance is computed from source i 0 , and G is the flow network derived by adjusting flow volumes based on airline suspensions, then the edge weights between nodes m and n on G arē F mn = F mn / n F mn , where F mn denotes the reduced flow between the nodes.