There are two aspects of the American prison system that stand out to David Skarbek: the massive size of the inmate population, and the inner workings of prison gangs. In his new book, The Social Order of the Underworld: How Prison Gangs Govern the American Penal System, he examined the role prison gangs play in facilities around the country. What he found may seem shocking – prison gangs can be ‘sophisticated organisations’ that help uphold the rules inside prisons, often to the benefit of many prisoners.

What are prison gangs doing right? Can corrections staff learn to better serve their inmates by studying these groups?

Find out more in Tim Newburn’s review at lse.ac.uk