This is a follow-up to question 348. Matthew Silverstein argues that "There is at least one good consequentialist reason for punishing attempted murder less severely than murder. If the two crimes are punished equally, then the law will not deter someone who has tried and failed to murder from trying again!" I guess this is plainly wrong. If someone tries twice she should be punished for two crimes, and the global penalty will be higher (perhaps two times higher). I can't see the difference between that case and the cases where someone commits two (accomplished) crimes of the same type against the same person (or, for that matter, against two different persons).

I agree that your solution works as well or better. Here are two different arguments a consequentialist might make. (1) Suppose all attempted murders are punished equally, regardless of success, with each attempt being punished with 6 years in jail and 30% of punished attempts successful. Now consider this reform: We increase punishment for successful attempts from 6 to 13 years and decrease punishments for unsuccessful attempts from 6 to 3 years. This reform leaves constant the jail time per punished attempt (which consequentialists typically count as a negative): 13 x 30% + 3 x 70% = 6. (Obviously, the numbers here are just for illustration.) But the reform is likely to increase deterrence, because prospective murderers are going to focus more on the "successful" outcome that risks a 13 year penalty than on the (actually more likely) "unsuccessful" outcome that risks a 3 year penalty. As a result of better deterrence, fewer murder attempts are made, fewer people are murdered, and fewer...