Do waiters and waitresses get better tips on sunny days? In 1979, a groundbreaking experiment by professor Michael Cunningham (currently at the University of Louisville) suggested the answer might be ‘Yes’. (reference : Weather, mood, and helping behavior: Quasi experiments with the sunshine Samaritan. Journal of Personality and Social Psychology, 37, 11, pp. 1947-1956.)
But now a newer study (from Scripps College and Stanford Law School) has obtained experimental data which queries the findings. Authors Sean Masaki Flynn and Adam Eric Greenberg explain :
“As previously discussed, Cunningham (1979) dealt with actual weather conditions by measuring light levels on 13 spring days and seeing how 130 customers (10 per day) tipped on those 13 days. He did find a positive correlation between light levels and tipping, but his sample was extremely small and he did not make any attempt to account for other factors that might have influenced tips.
“Finally, and perhaps most importantly, our study was conducted using receipts from only one restaurant. There is, consequently, no way to tell whether the tipping behavior observed at this particular restaurant would have been different if the restaurant had been transported to a different geographic location where it could have been exposed to a different customer mix.”
Nevertheless, the authors sum things up in one short, punchy sentence:
“Our primary finding is that weather did not significantly affect tipping behavior”
see: Flynn, Sean Masaki and Greenberg, Adam Eric (2011): Does weather actually affect tipping? an empirical analysis of time series data. Journal of Applied Social Psychology, Volume 42, Issue 3, pages 702–716, March 2012. A full version of the paper may be found here.
Further tipping explorations : Waitresses’ facial cosmetics and tipping: A field experiment