That is the case for some types of recidivism, where the individual who is convicted the first time is given a warning that if there were to be a second offence, a minimum sentence would apply. I am referring, for instance, to impaired driving. I understand that criminology principles and studies have established that this type of well-targeted short minimums may, indeed, have an effect on the crime rate.
On February 14th, 2011. See this statement in context.