Let’s abolish parole

The furore over the parole granted to John Worboys, the rapist taxi driver, misses the point entirely — that the system of parole is disgraceful in theory and irredeemably unwork-able in practice. The only thing that it is good for is the employment of large numbers of officials engaged in pointless or fatuous tasks who might other-wise be unemployed.

The system is predicated on the ability of experts to predict the future conduct of convicted prisoners. Will they or will they not repeat their crimes if let out early?

It is true that, using a few simple statistical measures, such as numbers of past convictions and age, you can predict this with an accuracy somewhat better than chance. But all further efforts to refine prediction actually reduce, not increase, accuracy. The problem of false positives and false negatives is inescapable — some people will be predicted to commit further crimes who will not, and some will be predicted to go straight who will break the law again.