I try not to watch politics programmes on TV. Andrew Neil's interview with Natalie Bennett about a basic income reminds me why.

I'm appalled by Natalie's inability to answer his first question: how to pay for it? The Citizens Income Trust has set out one way (pdf)* to do so: quite simply, abolishing the personal allowance and welfare benefits raises hundreds of billions.

Mr Neil's implication that a BI of £71pw is inferior to a personal allowance of £10,000 for the low paid is also wrong.

Take for example, someone earning £14,000 a year. She currently pays £800 in tax, giving a net income of £13,200. Under a basic income, she'd have to pay tax on all this £14,000. That's £2800. But she gets £3692 in BI. That gives a net income of £14,892. She's better off. BI, then, is better for the low-paid than the current £10,000 tax allowance.

This is even more true when we remember that low-paid work is often insecure. A BI is better for those who shift from work to unemployment and back again, as it ensures a continuous income with no threat of benefit delays.

In these senses, the interview was a car crash on both sides: Neil posing questions that are easily answered, and Bennett failing to answer even these.

This poses the question: what, then, are the more intelligent objections to BI?

The problem isn't that a BI gives too little to children, the disabled or pensioners. The CIT's costings show that they can get top-ups. Nor is it that a BI ignores housing costs. The CIT's costings show that housing benefit can be retained - though I personally think it should be phased out over time, as a big housbebuilding programme should reduce rents and hence landlord benefits.

Nor is it clear that a BI's treatment of immigrants is wrong. Because it's a citizens' basic income, immigrants would not be entitled to it - though they alternative insurance arrangements for them are possible and desirable. Such a restriction, though, should reduce public antipathy to immigration by removing the fears that they are "taking our benefits."

So, what are the more grievous problems?

One of the more common ones is that an unconditional income violates the norm of reciprocity and so would be unpopular. Dawn Foster says:

If you genuinely create a "something for nothing" culture - rather than one that exists merely in the fevered imaginations of tabloid readers - the backlash could be harsh.

To some extent,though, this is a feature, not a bug. Given that jobs are scarce it is just pointless and cruel to harrass the jobless into non-existent work. Indeed, helping some to drop out of exploitative jobs would force employers to improve their job offers, to the benefit of those who want to work.

However, it's doubtful how big a problem this is. Phil points out that it isn't a significant issue with Alaska's BI. And econometric simulations suggest it might not be for the UK either. In fact, insofar as a BI makes it easier to move into work - because there's no danger of losing income or of being better off on the dole - it might even reduce (pdf) unemployment.

For me, though, there are two other issues.

One is that a BI does create some losers. Anyone earning over £18,460 is worse off with a BI of £71pw than under a £10,000 personal allowance. This is a big problem. It suggests that a BI can only be popular if accompanied by more redistribution - higher taxes on the rich to pay for a lower tax rate on lower earnings and/or a higher BI.

Secondly, there's the question: is there the state capacity to effect such change? Everyone knows the shift to Universal Credit has been a mess. I'd like to think this because of Iain Duncan Smith's personal inadequacies. But it might also be that the state apparatus lacks the ability for reform. One of BI's great virtues - its simplicity and low administrative cost - also creates a big constituency in Whitehall opposed to it.

I suspect - hope - that there are solutions to this. A BI should not be introduced by the fiat of a single government. Instead, we need a new Beveridge report which would publicize its merits and ensure that it benefited as many people as possible. Only when it has such mass support should it be implemented.

* This is just one possible costing. Here's a list of tax reliefs (pdf). You can make up your own savings from these. And here's a collection of papers on basic income.