Related to this is that so far we’ve basically taken the homicide rate as exogenous, but of course there’s reverse causality. Having a large chunk of the population in prison will affect the murder rate. [...] Another way out for them is that maybe all the countries with similar homicide rates should imprison people as much as the US, but their institutions don’t function well enough.
Note that some people make the reverse argument: that a high imprisonment rate makes things worse, especially if the sentences are long and prison conditions are harsh and tending towards punishment rather than rehabilitation. People in prison end up socialized into interacting with other prisoners, which gets first-timers into a stronger criminal mindset. Once they get out, they might not have many opportunities available other than going back into crime.
At least this article notes that e.g. Finland has a low incarceration rate as well as a low recidivism rate, though the report that it cites for the recidivism figure explicitly concludes that the rates are not directly comparable between countries, so take that with a grain of salt.
Note that some people make the reverse argument: that a high imprisonment rate makes things worse, especially if the sentences are long and prison conditions are harsh and tending towards punishment rather than rehabilitation. People in prison end up socialized into interacting with other prisoners, which gets first-timers into a stronger criminal mindset. Once they get out, they might not have many opportunities available other than going back into crime.
At least this article notes that e.g. Finland has a low incarceration rate as well as a low recidivism rate, though the report that it cites for the recidivism figure explicitly concludes that the rates are not directly comparable between countries, so take that with a grain of salt.