I found the episode, but although it cited some sources, can't see an actual publication with that finding, but other sources plus some plausible conjecture by

I found the episode, but although it cited some sources, can't see an actual publication with that finding, but other sources plus some plausible conjecture by people who are fairly informed: Freakonomics Radio Episode #338 "How to Catch World Cup Fever" Jun 13, 2018 https://freakonomics.com/podcast/how-to-catch-world-cup-fever/ https://freakonomics.com/podcast/how-to-catch-world-cup-feve... [5m00s-onwards]" the World Cup isn’t just a gargantuan sporting event; it’s a microcosm of human foibles and (yep) economic theory brought to life." Click on 'Read Full transcript'. In the audio, jump to 11m29s, where they talk to Stefan Szymanski, professor of economics at the University of Michigan and co-author of Soccernomics.