PUNISHMENT is not wholly about value-for-money. If it were, we wouldn't spend thousands of pounds each year on every one of the 70,000 people we lock up in our prisons where their output is negligible.

If the Government really believes that its idea of removing benefits from persistent offenders is right, it should press on regardless of what is a huge cost.

Indeed, if spending a couple of thousand pounds on removing a person's benefits does shock them into realising their responsibilities - and keeps them out of an enormously expensive prison - it could argue that this is a value-for-money punishment.

So the debate about this policy should not centre on its cost. It should be all about its usefulness.

Will depriving people of benefits stop them from committing crime? Or will it, in fact, make them more likely to break the law?

The sad truth is that people who are going to be punished by this policy are likely to have come from poorer backgrounds - particularly if this idea is extended to the parents of children who play truant. Making them even more deprived will surely encourage them to increase their criminal activities, not turn their back on them.

The idea of stripping criminals of their benefits is superficially attractive. So was marching drunks to cash machines. So, for that matter, was the idea of building huge lengths of toll motorways to combat congestion.

The flaw with that last idea was that the new roads would only whizz even more traffic into our town and city centres and so cause even more congestion. Similarly, the removal of benefits seems likely only to whizz more people into crime.

The Government has to stop thinking about populist headlines. Instead, on crime, it should be quietly thinking about how to make community service into a real punishment.

Community service is regarded as a soft option. It is invisible. Even the footballer Jonathan Woodgate served his 100 hours in secret, and so the public has no idea how effective the punishment is.

But there's graffiti in town centres, churchyards are overgrown, school buildings are dilapidated. There are very visible projects which could be of great service to the community, and would allow the public to see a tangible return on the welfare payments which go to people who contribute little to society at present.