Can incarceration be thought of as disease?

Among its many marvels, some things about the United States of America are stubbornly unfathomable. The persistent, widespread opposition to socialised medicine is one of them. And despite a murder rate impressive for all the wrong reasons, US gun laws remain unreformed.

Add to this America’s prisons. This is not an area in which the United Kingdom basks in glory, but the American dedication to incarcerating its citizens remains without rival. “If this population had their own city, it would be the second largest in the country,” dryly remarks author Ernest Drucker.

The numbers tell the story: of a population of 310 million, 7.3 million people are under the control of the US criminal justice system. Of these, 2.3 million are imprisoned, 800 000 are on parole, and 4.2 million are on probation. The US has 5% of the world’s people but 25% of its prisoners. This section of the US population grew fivefold between 1970 and 2009.

Drucker, an …