In this week's Statbusters (link), we discuss two recent widely-shared articles, one on deaths while taking selfies, and the other on the gender gap in income among graduates of top-tier universities.
The common element between these two pieces is a reductionist analysis that looks at the correlation between a single variable X and an outcome Y when the outcome Y is affected by a multitude of variables. For example, it is reported that female graduates of Princeton or Harvard or Stanford earns $50,000 less annually than male graduates ten years after graduation. The two groups being compared do not differ just by gender, despite what that statement implies.
Note, however, that there is nothing wrong with the computation. Similarly, the deaths linked to taking selfies indeed outnumber deaths by shark attacks. The problem is that the analysis is misleading. It causes readers to come to the wrong conclusions.
Read the full article here.