Mandatory minimum sentences increase deterrence.  Deterrence works through several mechanisms; likelihood of getting caught, severity of punishment, and perceived public disapproval. Mandatory minimum sentences increase the effectiveness of severity as a deterrent. If potential criminals know a mild sentence is possible, they are more likely to commit crime in the hopes that they may charm a judge into sympathetically lowering their sentence. By establishing a set minimum punishment, a potential criminal with any knowledge of the penal code knows that, if caught, he/she will face a substantial punishment for his/her crime. The pro need not demonstrate that every, or even a strong majority, of would-be criminals will be deterred by mandatory minimum sentences; so long as the mandate has a reasonable deterrent effect, it will reduce crime and therefore improve the overall standard of living.