An amusing correlation (June 5, 2006) Category: Linear regression
I always like simple amusing examples that illustrate an important statistical point. An email by JW on EDSTAT-L offer a couple of examples.
The first is the statistician who reviewed fire department records and concluded the more fire engines you send to the scene of a fire, the more damage they cause. This is an example illustrating that it is not necessarily A causing B, but rather B causing A. I have used this example in my classes often.
A second example is good, and it is one that I had not heard before, though it is apparently used quite commonly. See for example, the Wikipedia entry on correlation and causation:
This example shows a strong correlation between ice cream sales and crime rates. The "obvious" interpretation is that ice cream causes crime. A more logical interpretation is that both ice cream sales and crime rate are correlated with outdoor temperature.
This web page was written by Steve Simon, edited by Steve Simon, and was last modified on 09/24/2007.