A term used to describe a situation where two variables (X and Y, say) are correlated without being causally related to one another. The usual explanation is that they are both related to a third variable, Z. Often the third variable is time. For example, if we compare the price of a detached house in Edinburgh in 1920, 1930,…with the size of the population of India at those dates, a ‘significant’ positive correlation will be found, since both variables have increased markedly with time. The first comprehensive study of nonsense correlation was undertaken in 1926 by Yule, who considered the apparent connection between the fall in Church of England marriages and the concurrent increase in life expectancy. See also gooseberry bushes; rum consumption.
Subjects: Probability and Statistics.