I think you can get some useful insights into the reasons why punishments might differ based on moral luck if you take an ex ante rather than an ex post view. I.e. consider what effect the punishment has in expectation at the time that Alice and Yelena are deciding whether to drive home drunk or not, and how recklessly to drive if they do.
Absent an extremely large and pervasive surveillence system, most incidences of drunk driving will go undetected. In order to acheive optimal deterence of drunk driving, those that do get caught have to be punished much more. While drunk drivers will face different punishments ex post, the expected punishment they face ex ante will be the same. If there are in fact factors that make your drunk driving less dangerous (less drunk, more skilled driver, slower speed, etc.), these will decrease the expected punishment.
So basically, the ex ante expected punishment for a particular dangerous act does not differ based on moral luck. Ex post punishment does differ, and that is a cost,
but the countervailing benefit of not having a costly and intrusive surveillence system outweighs it I think.
This argument applies much less in the attempted murder / murder case, because the chance that an attempted murder is caught and prosecuted is much higher, probably even higher than the probability a murderer is caught (because the victim usually has lots of relevant information).
For the purposes of this comment, I considered drunk people to be rational actors. They are not, but this is a nonissue, because drunk selves are only allowed to exist at the discretion of sober selves.
Further, it’s plausible that if you had a ‘budget’ of N prison places and M police officers for drink-driving deterrence, the most effective way to deploy it would be to arrange for a highish probability of an offender getting a short prison sentence, plus a low probability of getting a long sentence (because we know that a high probability of being caught has a large deterrent effect, and also that people overestimate the significance of a small chance of ‘winning the lottery’).
So the ‘high sentence only if you kill’ policy might turn out to be an efficient one (I don’t suppose the people who set sentencing policy are really thinking along this lines, though).
and also that people overestimate the significance of a small chance of ‘winning the lottery’
But people also play Martingale systems on roulette. These have a good chance of going well, and a small chance of going really, really, badly. So people don’t just overestimate small chances. I think they tend to overestimate the probability of events that benefit them, but this may depend on whether they are in near mode or far mode. If they were in far mode they might begin to fret more and more about the small probabilities.
I think you can get some useful insights into the reasons why punishments might differ based on moral luck if you take an ex ante rather than an ex post view. I.e. consider what effect the punishment has in expectation at the time that Alice and Yelena are deciding whether to drive home drunk or not, and how recklessly to drive if they do.
Absent an extremely large and pervasive surveillence system, most incidences of drunk driving will go undetected. In order to acheive optimal deterence of drunk driving, those that do get caught have to be punished much more. While drunk drivers will face different punishments ex post, the expected punishment they face ex ante will be the same. If there are in fact factors that make your drunk driving less dangerous (less drunk, more skilled driver, slower speed, etc.), these will decrease the expected punishment.
So basically, the ex ante expected punishment for a particular dangerous act does not differ based on moral luck. Ex post punishment does differ, and that is a cost, but the countervailing benefit of not having a costly and intrusive surveillence system outweighs it I think.
Notes:
This is the second time I’ve linked this recently, but Gary Becker’s Crime and punishment: An economic approach is a very useful way to think through these issues.
This argument applies much less in the attempted murder / murder case, because the chance that an attempted murder is caught and prosecuted is much higher, probably even higher than the probability a murderer is caught (because the victim usually has lots of relevant information).
For the purposes of this comment, I considered drunk people to be rational actors. They are not, but this is a nonissue, because drunk selves are only allowed to exist at the discretion of sober selves.
Further, it’s plausible that if you had a ‘budget’ of N prison places and M police officers for drink-driving deterrence, the most effective way to deploy it would be to arrange for a highish probability of an offender getting a short prison sentence, plus a low probability of getting a long sentence (because we know that a high probability of being caught has a large deterrent effect, and also that people overestimate the significance of a small chance of ‘winning the lottery’).
So the ‘high sentence only if you kill’ policy might turn out to be an efficient one (I don’t suppose the people who set sentencing policy are really thinking along this lines, though).
But people also play Martingale systems on roulette. These have a good chance of going well, and a small chance of going really, really, badly. So people don’t just overestimate small chances. I think they tend to overestimate the probability of events that benefit them, but this may depend on whether they are in near mode or far mode. If they were in far mode they might begin to fret more and more about the small probabilities.