Best available evidence is that:

- Punishment works to deter crime when it's immediate and high-likelihood. Particularly, if someone gets caught and faces some immediate consequence on one of the first few times they shoplift (especially the first time) then that makes a huge difference to the probability that they'll become a habitual shoplifter

- The vast majority of shoplifting is done by a small number of essentially lifelong career shoplifters. Imprisoning them is unlikely to set them straight, but taking them off the streets for long periods makes a significant impact on the amount of shoplifting the community experiences