Today, the M.C.C. model of incarceration, which is now known as “direct supervision,” is not entirely dead. Around 350 facilities — making up less than 7 percent of the incarceration sites in the United States, mostly county-­level jails, which are pretrial and short-­stay institutions — have been built on the direct-­supervision model and are, with greater and lesser fidelity to the ideal, run by the same principles of inmate management developed for the new-­generation prisons of the 1970s. The body of data from those jails over the last 40 years has shown that they have lower levels of violence among inmates and against guards and reduced recidivism; some of these institutions, when directly compared with the older facilities they replaced, saw drops of 90 percent in violent incidents. But extrapolating from this tiny group of facilities to the entire nation, and in particular to its maximum-­security prisons, is an impossible thought experiment. Much about the American culture of imprisonment today — the training of guards, the acculturation of prisoners, the incentives of politicians, the inattention of citizens — would have to change for the Norwegian approach to gain anything more than a minor foothold in the correctional system. The country has gone down a different road during the past half century, and that road does not lead to Halden Fengsel.

Even understanding how well the Norwegian approach works in Norway is a difficult business. On a Saturday afternoon in Oslo, I met Ragnar Kristoffersen, an anthropologist who teaches at the Correctional Service of Norway Staff Academy, which trains correction officers. Kristoffersen published a research paper comparing recidivism rates in the Scandinavian countries. A survey of inmates who were released in 2005 put Norway’s two-­year recidivism rate at 20 percent, the lowest in Scandinavia, which was widely praised in the Norwegian and international press. For comparison, a 2014 recidivism report from the United States Bureau of Justice Statistics announced that an estimated 68 percent of prisoners released in 30 states in 2005 were arrested for a new crime within three years.

I asked Kristoffersen if he had spent time at Halden. He reached into his briefcase and pulled out a handful of printed sheets. “Have you seen this?” he asked while waving them at me. “It’s preposterous!” They were printouts of English-­language articles about the prison, the most offensive and misleading lines highlighted. He read a few quotes about the prison’s architecture and furnishings to me with disgust. I acknowledged that the hyperbolic descriptions would catch the attention of American and British readers, for whom the cost of a prison like Halden would probably need to be justified by strong evidence of a significant reduction in recidivism.

Somewhat to my surprise, Kristoffersen went into a rant about the unreliability of recidivism statistics for evaluating corrections practices. From one local, state or national justice system to another, diverse and ever-­changing policies and practices in sentencing — what kinds and lengths of sentences judges impose for what types of crimes, how likely they are to reincarcerate an offender for a technical violation of parole, how much emphasis they put on community sentences over prison terms and many other factors — make it nearly impossible to know if you’re comparing apples to apples. Kristoffersen pointed out that in 2005, Norway was putting people in prison for traffic offenses like speeding, something that few other countries do. Speeders are at low risk for reoffending and receiving another prison sentence for that crime or any other. Excluding traffic offenders, Norway’s recidivism rate would, per that survey, be around 25 percent after two years.

Then there was the question of what qualifies as “recidivism.” Some countries and states count any new arrest as recidivism, while others count only new convictions or new prison sentences; still others include parole violations. The numbers most commonly cited in news reports about recidivism, like the 20 percent celebrated by Norway or the 68 percent lamented by the United States, begin to fall apart on closer inspection. That 68 percent, for example, is a three-­year number, but digging into the report shows the more comparable two-­year rate to be 60 percent. And that number reflects not reincarceration (the basis for the Norwegian statistic) but rearrest, a much wider net. Fifteen pages into the Bureau of Justice Statistics report, I found a two-­year reincarceration rate, probably the best available comparison to Norway’s measures. Kristoffersen’s caveat in mind, that translated to a much less drastic contrast: Norway, 25 percent; the United States, 28.8 percent.

What does that mean? Is the American prison system doing a better job than conventional wisdom would suggest? It is frustratingly hard to tell. I asked Kristoffersen if that low reincarceration rate might reflect the fact that long prison sentences mean that many prisoners become naturally less likely to reoffend because of advanced age. He agreed that was possible, along with many other more and less obvious variables. It turned out that measuring the effectiveness of Halden in particular was nearly impossible; Norway’s recidivism statistics are broken down by prison of release, and almost no prisoners are released directly from maximum-­security prisons, so Halden doesn’t have a recidivism number.