Do Uncommon Names Turn Kids Into Criminals?

Photo: tomeppy

The answer to that question is almost certainly “no,” but a new study that is getting lots of media attention does claim that there is a correlation between having an uncommon name and being more likely to show up in the juvenile justice system. The study finds this relationship to be true both for blacks and whites.
As the authors clearly state in the abstract of their paper, “Uncommon names are likely not the cause of crime but correlated with factors that increase the tendency toward juvenile delinquency.”
To me, that makes the result a lot less interesting. It is kind of like saying that we know that people who regularly wear orange jumpsuits are more likely to be criminals, when orange jumpsuits just happen to be the required uniform in the state prison. The wearing of orange jumpsuits isn’t the cause of the criminal activity, but it is highly correlated with past criminal involvement.
And to be honest, I think there is a good chance that even the claimed correlation between unusual names and criminality is wrong. I only quickly glanced through the academic paper, but it seems to me like the authors have made a mistake that will bias their results.
The authors first compute criminality for each name by taking the ratio of the number of juvenile delinquents with that name and dividing it by the number of children total with that name. The higher that ratio, the more criminal the name. But then the authors take the log of that ratio. The problem is that the log of zero is equal to negative infinity, so any name for which that ratio is equal to zero gets dropped from the analysis.
The kinds of names that will have a ratio of zero are uncommon names for which no one with that name is a juvenile delinquent.
If I understand correctly what they are doing, if exactly one person has a particular name, the only way that the observation for that name will be included in their sample is if that person is a juvenile delinquent! This leads to a powerful bias toward mistakenly concluding that people with uncommon names are more likely to be criminals.