Spurious Correlation

Does the NASDAQ go up when the Mets are winning? Do you step in dog poop on cloudy days? Does crime go down when a new police chief comes to power?

Some things aren’t causation, just correlation. Just because two variables are correlated doesn’t mean they have anything to do with each other. Spurious correlation is sometimes caused by another unseen factor. Other times, it’s just coincidence. Or, more statistically correct: random chance.

For instance, the skyscraper effect is the theory that the construction of the world’s next tallest skyscraper means an economic recession is nigh for that country. There’s probably not enough data or evidence to draw statistical significance from this, but a third factor involved is this: skyscrapers beating the world record are likely being built at a country’s economic peak...and economic peaks oftentimes come right before recessions in the business cycle.

Other times, it’s just chance. Think about it: things can only go up, go down, or stay the same. It would be crazy if things didn’t spuriously correlate sometimes.