The Steelers, the Stock Market, and Spurious Correlation

The USA Today reports today that the stock market has performed quite well during years in which the Pittsburgh Steelers have won the Super Bowl. In fact, the stock market has clearly done better when the Steelers emerge victorious than when other teams win the Super Bowl. Of course, it doesn't mean we should all run off and root for the Steelers in hopes that it will restore our 401K plan balances. This is a classic example of spurious correlation... and a good example for reminding students about not being fooled into thinking such correlations imply causation.