Something to consider.

In the days when you could be hanged for stealing a small amount of goods, there were several ways of viewing such harsh penalties.
The first was that hanging could not possibly deter somebody who lived in absolute poverty as theft gave a chance of life with just a risk of death, whereas death through the poverty was perhaps inevitable. A justifiable risk, then.
No. It was only the people who had something to lose who could be deterred - and clearly they were. It is only under such extreme circumstances that it may be reasonably argued that 'only the poor generally hang'.
A second point is that in those severe days even the very worst of mothers impressed upon their children the consequences of their actions; the dangers of the gallows. I wonder how many mothers from the anti-social underclass of today encourage their offspring not to steal - or worse - as the consequences are so terrible?