Simon Carr: First rule of politics: no one ever knows what's going on

After the last election, the cull in the Ministry of Culture was unusually severe. Their Dome-failures, their Wembley-fiasco drew brutal reprisals. Every last minister was struck down. Now a new team is in place. A new strategy is surely being developed. It'll be over-arching, if experience is anything to go by, regionally weighted and based on locally autonomous partnership charters. It's unlikely anything will change for the better, not observably. Why should it?

When I wrote advertising copy, we were ruled by account directors. They liaised with the clients and were in charge of selling the stuff we produced. The grossest failures on the client side, the worst nerve-losses, the most random, ridiculous and inexplicable decisions, were glossed by the words: "It's political." Don't ask, don't argue, it may not make sense, but accept what you're told because "it's political."

The significance of that phrase is only now becoming clear.

A new study by Sara Selwood published by the Policy Studies Institute looks at the UK cultural sector. Her report reveals the most basic reality of political endeavour: nobody knows what the hell is going on.

Even the basics aren't available. Nobody knows how much subsidy money is disbursed, who or how many are the beneficiaries, nor what the audiences are. In the absence of such data, it's impossible to say how well arts policy has performed. Maybe that's how the policy-framers want it,.

"How can we have evidence-based policy when there's no evidence?" the report asks. It's a rhetorical question.

Sara Selwood estimates the subsidy spend at around £5.5bn – not far short of what the Home Office spent on crime prevention in the same year. It's a Dome for five cities. It's tuppence off income tax. It's an army. It's a cornucopia of schools and hospitals.

Arts subsidy comes from sources as diverse as the lottery, local authorities, charities and the Government's Single Regeneration Budget. A surprisingly small amount comes from the Ministry of Culture (14 per cent, according to Ms Selwood).

As you would expect, the ministry is the last place to look for an overall view. But there are questions that it could try to answer, some harder than others.

How much arts subsidy is coming from the European Union should be relatively easy. No one knows. Is subsidised theatre more innovative for being cushioned against commercial demands? That's harder. Sara Selwood found no evidence it was so. Indeed, when a massively subsidised National Theatre is staging My Fair Lady and Oklahoma, the argument is turned on its head.

Why are subsidised films so unsuccessful? Why do politicians think they can turn artists into engineers of social inclusion? If the rhetoric is to be taken seriously, and areas of need are to be targeted, why aren't funds diverted from the Royal Opera to projects in Oldham and Bradford?

The state's arts policy is slung up on a number of New Labour poles. Access. Social inclusion. Excellence. Lifelong learning. For the many, not the few. It's a well-meaning policy, insofar as it means anything.

Some targets are capable of measurement. Chris Smith, the former Secretary of State for Culture, beamed that Tate Modern had attracted 5.5 million people in its first year (it wasn't true: there'd been 5.5 million visits – what's that? Three million visitors? Nobody knows).

They are also attaching a range of performance indicators to cultural institutions with Soviet zeal – 8 per cent more Diwali children at the opera, that sort of thing. More D2s at the theatre, more children of single-parent families at the ballet.

With a Soviet symmetry, they've got no idea how they're doing. The evidence is against them. When you break down attendance at, say, a Canaletto exhibition, you find it's almost exclusively ABC1s. The more you ease access (by touring it or subsidising tickets or keeping it open all night) the more ABC1s you get. This may be because Canaletto is a bourgeois, European painter, or more broadly that art, these days, is a bourgeois pursuit. It was not always so, but these days, culture has become as tribal as politics.

As to what the socially included audience gets out of their government-sponsored cultural experience, that's unavailable, and more than likely unknowable. Baroness Blackstone certainly said so on the radio: they couldn't measure excellence so they weren't going to try. And considering that excellence and social inclusion are, broadly speaking, incompatible objectives, that's probably just as well.

Arts subsidies have increased to record levels, and yet ballet and theatre audiences are steadily declining. Yet more spending is promised by the ministry – up by 60 per cent over the next couple of years (of course this is much less than it appears at first sight).

But who's to say that greater government involvement with their targets and performance indicators won't accelerate the decline?

It's political, after all.