Abstract: Despite a declining prison population, the US still sends more people to jail per capita than any other country. But does this predilection towards incarceration lead to lower crime rates? By relating crime and incarceration data to country-specific data on measures such as development and social policy Holger Spamann finds that the US’ incarceration rate is a distinct outlier given the amount of crime it experiences. He writes that the incarceration gap may be down to factors such as poor race relations, but that it is more likely that the US’ policy of mass incarceration simply doesn’t do enough to deter or prevent crime.