Abusing Statistics
I recently learned an interesting new way to abuse statistics using regressions. (I’ll describe it first in a way that requires no math background, and give some math details at the end.) It can be difficult to tell if those who abuse statistics are dangerous and well-intentioned or dangerous and know fully what they’re doing. Either way, they’re dangerous. Suppose we conducted a study of retirees in their 60s to find out what percentage of their portfolios they spend each year. Even though this percentage varies across retirees, we want to get an overall sense of whether they’re spending too little or too much. For the raw data of the study, I’m going to choose unrealistically simple numbers to make the calculations easier. The purpose here is to illustrate abuse of statistics. Here’s the raw data: 1000 retirees have $100,000 saved and spend $6000/year. 100 retirees have $1 million saved and spend $40,000/year. 10 retirees have $10 million saved and ...