This is a really interesting question that gets at some recent themes discussed in other Quora questions (
The answer to your question about the Norwegian sentencing system likely lies somewhere in there as well.
There are essentially five goals of sentencing:. The last of these, rehabilitation, is probably one of the most controversial. In the U.S., for example, rehabilitation is considered a secondary goal, after retribution. Americans want their prisoners punished first and rehabilitated second.
This appeals to a societal sense of justice and fair play that has considerable cultural inertia in our country. Any talk of prioritizing rehabilitation ahead of retribution very typically generates complaints about how doing so will endanger public safety, ignore the needs of crime victims, and—most damning of all—coddle criminals.Never mind that certain forms of rehabilitation have been shown throughto reduce the risk of future offending, we want our pound of flesh first and foremost.
The same is not true the world over, though. Norway, by contrast, has a very progressive approach to sentencing that prioritizes rehabilitation as a primary strategy for reducing future criminal behavior. That doesn't mean they don't use prisons, it just means that the conditions of confinement are geared toward reducing the risk that an offender will return to a life of crime after release
Unlike many U.S. jurisdictions that use determinate sentencing (the sentence stated by the court is the actual sentence that will be served), Norway uses an indeterminate system that relies on an assessment of whether or not the offender is rehabilitated as a basis for release from prison.
As you noted, the stated maximum prison sentence in Norway is 21 years, but that can also be extended in five-year increments if the prison system determines that an offender is not rehabilitated by the end of his or her initial term. They can be extended in this way, every five years, indefinitely. So, essentially, there is an ability for an individual to serve life in prison, it's just decided on an installment basis.
The outcomes of this approach seem to be positive in terms of reducing the risk of reoffense. I couldn't find a more authoritative source, but this Guardian article aboutsystem claims that the recidivism rate of Bastoy Prison is about 16 percent, the lowest in Europe, versus in the U.S.
Sentencing practices and the conditions of confinement in Norway aren't without controversy of their own, however. There's been heated debate across Europe about the perceived injustice of Norwegian inmates living in relative "luxury" while the living conditions for impoverished or elderly law-abiding people aren't nearly so comfortable.
The question of whether prisoners should enjoy better living conditions than law-abiding people, even if those conditions are part of what leads to more positive rehabilitative outcomes is a legitimate one. At this point, at least, Norway has chosen an approach that it generally believes will have the greatest positive impact on crime.
Limits to the length of prison sentences are one component of that approach.
More questions on criminal justice: