There is an issue here of correlation and causation. It is true that people who serve 40 or 50-year sentences are less likely to reoffend, for two reasons. The first relates to the offence type. For example, murderers are generally less likely to reoffend than shoplifters. Secondly, the mere fact that they are locked away for 40 or 50 years makes it difficult for them to reoffend. Generally, short-sentence prisoners who are in for under 12 months are overwhelmingly dominated by chaotic individuals who often have drug or alcohol problems and who often commit offences such as shoplifting. They are a much more difficult target group to deal with than the people who are locked away for 40 or 50 years.