Judging from the overcrowding in prisons and the call to reform our penal system, the answer seems to be negative. Also the rate of recidivism is also great. This basically means that people who served time often times go back to serve further time. This last point is very strong evidence that something needs to be done. There are probably a number of reasons for this.
1. What are those who were once in prison supposed to do when they get out? If there is nothing or little, they may break laws once again.
2. Prison programs may be weak. In other words, one who is jail might not learn a marketable skill for when they get out.
3. Even when prisoners get out, there might not be enough of a social network.
Although it's impossible to know the answer to this question, my argument is that it does not.
My only specific evidence for my opinion is that recidivsm rates (rates of prisoners committing crimes again after being released) is extremely high.
Why reasoning is this: prisoners do not receive very much in the way of help in improving themselves to the point where they will be able to make an honest living after release. Instead, they have a criminal record and no skills other than more criminal skills that they learn from talking to fellow prisoners.
So our prison system does little to rehabilitate prisoners and therefore doesn't really reduce crime.