The Effect of Social Distancing on the Reach of an Epidemic in Social Networks

I met my coauthor Tomohiro Hirano in 2013 when I gave a job talk at University of Tokyo. We stayed in touch, for instance I invited him to the macro seminar at UCSD in 2015 where he presented his REStud paper on rational bubbles, and he also invited me several times to conferences and seminars. In March 2020, right before COVID, I gave a talk at Royal Holloway and met Tomohiro and his colleague Philip Neary. Philip told me he had an Erdős number of 3 through the coauthorship with the computer scientist Gregory Gutin. At that time, my Erdős number was 5, so I was interested in getting the number down.

We then joked that perhaps we can write a paper together so that both Tomohiro and I could get the Erdős number 4 through the coauthorship with Philip. When COVID hit, Philip had an idea about an SIR model on a network, so we decided to write a paper together. We got greedy and then invited Gregory as a coauthor to get the Erdős number 3.