Austrians are currently agonizing over whether the maximum sentence of 15 years for Josef Fritzl---the man who kept his daughter captive in a windowless, sound-proof vault for 24 years, fathering 7 children by her---is sufficient punishment for such monstrous crimes. As a practical matter, the answer is probably yes. Fritzl is currently 73, and so, based on the most recent Austrian life-expectancy data, a 15-year sentence is more likely than not a life sentence. It's very much more likely than not a life sentence if Fritzl is convicted of "murder through failure to act" in connection with the death of one of the children his daughter bore him. That crime carries a potential 20 year sentence.
I strongly suspect, however, that Austrians are not so much outraged at the small possibility that Fritzl might emerge from prison at 88 or 92 and commit further crimes. Rather, the worry is over the apparent inadequacy of the moral condemnation expressed by a 15 or 20 year sentence.
That's not to say there is no practical dimension to too-lenient sentences---even in this case. According to Fritzl's sister-in-law, he had previously served time for a 1967 rape conviction. How much time? 18 months. A substantially longer sentence for that earlier offense might well have eliminated Fritzl's opportunity to commit the rapes of his daughter or, after his release, might even have specifically deterred him (although the recidivism rate for sexual offenders is high even in the U.S., with its much more substantial sentences).
Here in the U.S., we generally have the opposite problem: Too many people in prison for too long. As a recent NY Times story reported, over one percent of the adult population in the United States is in prison or jail. One in nine black men between the ages of 20 and 34 is incarcerated!
Does the juxtaposition of the Fritzl case and the bursting-at-the-seams story of American incarceration show that you're damned if you do, damned if you don't? Must societies either under-incarcerate or over-incarcerate? Almost certainly not. Seen properly, these are not tradeoffs but the same problem: In both Europe (in cases like Fritzl's) and in the United States (in large part, but not exclusively, as a consequence of the disastrous war on drugs), we have a failure to make the punishment fit the crime.
Posted by Mike Dorf