With the greatest of respect, the evidence really flies in the face of the notion that the length of a sentence has any deterrent effect at all.
Professor Parkes could probably speak to that with a little more data behind her. I think that's what Professor Parkes was getting at in the need for comprehensive sentence reform. A lot of the piecemeal measures that we have seen over the last 15 years have been premised on this faulty premise that lengthening the availability of a sentence has an impact.
What has a bigger impact is the likelihood of getting caught, for example. Unfortunately there is a real fallacy in that proposition.