You Make Pearson Cry #1: Stay Together for the Money December 11, 2006Posted by Johan in Off Topic, Rants, You Make Pearson Cry.
The British Conservative Party launched a report today, which inspired me to create a new feature for this blog: you make Pearson cry, named after the man who did the first work on correlation, and whom the Pearson correlation coefficient is named after. Of course, I have no idea what Pearson might have thought about inappropriate use of his measure of effect size. After all, the man was a eugenicist, for whom confusing correlation and causation is par for the course. It’s that very confusion which will be the topic of this feature.
The report seems to be quite wonderful in its blatant disregard for what might be inferred from a correlation. Case in point:
“Iain Duncan Smith’s report for the Tories on poverty, found family splits caused social problems costing £20bn.” (BBC)
So, you’ve figured out that divorced parents have more social problems, and that their kids get into more trouble. So far so good. Next, you conclude that if they stayed together, you wouldn’t have a problem. Umm, no. There are a million other variables with also differ between people who have problems and people who don’t, and it seems a bit idiotic to believe that of all those, it isn’t a family history of poverty and social problems; it isn’t drug use; it isn’t screwing up school. No. Instead, marital status is the underlying cause of all these! So what do we do?
“Couples should be “encouraged to get together and stay together” – possibly with the help of changes to taxation to support marriage, Mr Cameron said” (BBC)
We buy them off. Clearly some of these couples that split up, thus causing, in essence, the downfall of the British Empire, would stay together for purposes of taxation. We all know how great it is when parents stay together for the kids. Now parents who don’t care about the kids can still stay together for the money, which is likely to result in everyone living happily ever after, according to Mr Cameron.
Just to be clear: this proposal is really looking out for the poor. It has absolutely nothing to do with the Conversative constituency being made up of married couples who like tax breaks.