WE RECENTLY wrote about how a tattoo affects your job prospects. A paper from Kaitlyn Harger, a PhD student at West Virginia University, takes it a step further. Ms Harger found data from Florida and looked at what happened to people when they left prison. But her dataset was different: she knew which prisoners were tattooed.

Lots of employers are loth to employ people with tattoos. The US Army, for example, recently tightened its rules on body art. Ms Harger suggests that tattooed ex-cons, shunned by the legal labour market, slip back into criminality as a means to earn a crust: hence higher recidivism.

Her results are striking. On average, someone lasts 5,000 days (about 14 years) before finding themselves back in the cooler. A tattooed ex-con lasts half that (see chart).