Tuesday, July 30, 2019

Correlation, causation, and deceitful charts

Enrico calls my attention to a tweet by notorious grifter Charlie Kirk. Kirk wants you to see a “correlation” in the fact that “America's worst run cities” haven't had Republican mayors in decades. That's bullshit.

Bullshit was already pervasive when Harry G. Frankfurt wrote his classic, and its presence in the public arena has only increased. I suspect that Kirk intuits there's something fishy about his “correlation” and doesn't care. That's the very definition of bullshit: facts can be true or not and still be bullshit because of how you employ them. It all depends on whether you care about the truth, and not about how you want to be perceived. Here's Frankfurt:
Someone who lies and someone who tells the truth are playing on opposite sides, so to speak, in the same game. Each responds to the facts as he understands them, although the response of the one is guided by the authority of the truth, while the response of the other defies that authority and refuses to meet its demands. The bullshitter ignores these demands altogether. He does not reject the authority of the truth, as the liar does, and oppose himself to it. He pays no attention to it at all. By virtue of this, bullshit is a greater enemy of the truth than lies are.
(Side note: this interview with Frankfurt is great.)

There's so much wrong with Kirk's tweet that it's hard to decide where to begin. For instance: Are cities run like schools or prisons, with principals or wardens that exert absolute control? Of course not. Cities are organic, chaotic entities. Are those cities on the list really the “worst” in the U.S.? What do you mean by “worst”? How do you measure that? After all, many small towns and rural regions have dreary health and life quality metrics.

I happen to know all those cities; they do face challenges (crime, poverty, homelessness,) but they are also wealth, science, culture, and creativity hubs. When a human group increases in size, extremes—both positive and negative—become more likely and visible. That's a matter of probability. Moreover, does having Democratic mayors for decades lead to being “worst”, or does the fact that these are big cities—with tons of racial and ethnic diversity, and plenty of highly educated people—lead to electing Democratic mayors? Causality is complicated.

How Charts Lie is devoted to explaining how we lie to ourselves with charts—numerical tables like Kirk's, graphs, maps, infographics—that may or may not be designed to deceive. The intentions behind a chart are secondary in comparison to the fact that we are all prone to projecting what we want to believe onto whatever we see or read. We can do better. Judging by the responses to Kirk's tweet, many from people persuaded by his “correlation”, we still have lots of work to do.