I don’t know whether the value I get from revenge is greater than the value I get from decreased danger, but I am almost sure that would depend on exact numbers and there would be a threshold T of probability for each crime. So, for example, let P = present law and H = hypothetical law which doesn’t punish murder and p(M) = murder rate; I would prefer H to P iff p(M | H) is lower than T(murder). I am not certain what T(murder) actually is, but it may also depend on p(M | P). To say at least something, I would prefer P to H if p(M | P) - p(M | H) < 10^(-8) , and I would prefer H to P if p(M | H) < 10^(-8).
If you want to survey about values attributed to retribution, you could probably do it more directly without assuming an inplausible scenario. Just: “Would you choose to do action X, if the consequences were (1) reduction of crime rate by amount Y, and simultaneously (2) no punishments for crimes?” There is no need to assume that (2) is the cause of (1); doing so primes people to concentrate on the implausibility instead of the core of your question.
A reformulated remotely plausible version of the thought experiment: I am a rich experimental psychologist / experimental ethicist / sociopath. You are dictator of a city state with 1 million inhabitants. I offer you to install a super-powerful automatic security system if and only if you agree to abolish all punishments. The automatic system covers your entire city by surveillance cameras and detects all crimes. Moreover, there are robots which can prevent 99% of crimes (private retributions included) from happening, and experiments show that the increase of attempted crimes in the absence of punishment is only by factor of 10. This means that the overall number of committed crimes decreases 10 times. Would you accept my offer?
Least convenient possible world, of course: you have absolute power, so no real chance to be overthrown because of making unpopular decisions; the security system is safe and destroys all records after they are of no use for the crime-preventing robots, so no disutility associated with loss of privacy; etc.
I don’t know whether the value I get from revenge is greater than the value I get from decreased danger, but I am almost sure that would depend on exact numbers and there would be a threshold T of probability for each crime. So, for example, let P = present law and H = hypothetical law which doesn’t punish murder and p(M) = murder rate; I would prefer H to P iff p(M | H) is lower than T(murder). I am not certain what T(murder) actually is, but it may also depend on p(M | P). To say at least something, I would prefer P to H if p(M | P) - p(M | H) < 10^(-8) , and I would prefer H to P if p(M | H) < 10^(-8).
If you want to survey about values attributed to retribution, you could probably do it more directly without assuming an inplausible scenario. Just: “Would you choose to do action X, if the consequences were (1) reduction of crime rate by amount Y, and simultaneously (2) no punishments for crimes?” There is no need to assume that (2) is the cause of (1); doing so primes people to concentrate on the implausibility instead of the core of your question.
A reformulated remotely plausible version of the thought experiment: I am a rich experimental psychologist / experimental ethicist / sociopath. You are dictator of a city state with 1 million inhabitants. I offer you to install a super-powerful automatic security system if and only if you agree to abolish all punishments. The automatic system covers your entire city by surveillance cameras and detects all crimes. Moreover, there are robots which can prevent 99% of crimes (private retributions included) from happening, and experiments show that the increase of attempted crimes in the absence of punishment is only by factor of 10. This means that the overall number of committed crimes decreases 10 times. Would you accept my offer?
Least convenient possible world, of course: you have absolute power, so no real chance to be overthrown because of making unpopular decisions; the security system is safe and destroys all records after they are of no use for the crime-preventing robots, so no disutility associated with loss of privacy; etc.