Perhaps, he thought, Mormons don’t care if their kids get hurt in a car accident.
It was the early 1990s, and I was in grad school at the University of Oregon. I was in the Public Affairs program taking an economics class, and our professor was giving an example of how baseline data matters.
Some years earlier, he’d lived in Salt Lake City, and he started noticing something as he drove around town: He was seeing a noticeable number of cars with the kids not in carseats. So many, in fact, that he began to question if people there were concerned for their children’s safety.
He knew this thought was wrong. Family is precious to Mormons, literally sacred in fact. There had to be something else involved, and, being an economics professor with a strong grounding in statistics, he finally figured it out: Baseline.
Simply put, there were so many young families in SLC, so many people driving with kids in their cars, that of course he was seeing more cars without carseats than he was used to. He had not accounted for the change in baseline: the fact that he was also seeing more cars-with-kids than he was used to.
The baseline for “families with small kids in cars” is pretty big in Salt Lake City. So if they have the same ratio of cars not using safety seats as, say, Portland, the gross number is going to be larger. Those cars will stand out because there are more of them.
When we look around us and make an observation about public behavior – eg, the number of rude, inconsiderate, scofflaw bicyclists – we have to understand the baseline data. In Portland, we have a relatively huge number of people riding bicycles,...