Throwing more money at the NHS in a bid to match health spending in other countries will only create a self-defeating cycle of higher and higher expectations, writes John Appleby

How much do we need to spend on the NHS to match the EU average in terms of total spending on healthcare as a percentage of gross domestic product? This apparently straightforward question turns out to be very difficult to answer.

First, how much does the UK currently spend on all forms of healthcare? The latest Organisation for Economic Co-operation and Development answer to this is 6.8 per cent of GDP in 1997. The Office for Health Economics, on the other hand, says 6.6 per cent for the same year.

Taking gross UK NHS spending figures for 1997 as detailed in the Department of Health's 1999-2000 expenditure plans -£44.975bn - and adding£7.3bn private spending reported by the OHE, then dividing by the GDP figure provided by the Office of National Statistics -£814.69bn - the percentage spend is 6.4 per cent.

What the percentage spend is now, as opposed to 1997, is probably anyone's guess. So it's not clear where the UK starts from. It's also unclear where it's got to get to.

The government's favoured figure for the EU average spend on healthcare is 8 per cent. But this is in fact an unweighted average of the percentage figures for the 15 countries currently comprising the EU. The weighted average - treating the EU as one big country - is 8.6 per cent. The difference may seem small, but 0.6 per cent of the UK's current GDP is equivalent to£5.34bn.

Is this all mere quibbling? If the prime minister's pledge (aspiration? ) is to give the NHS a real-terms increase of 5 per cent each year, up to and including the financial year 2005-6, then this is a set of increases almost unprecedented since the NHS first began - which is nice. Only in a five-year period at the beginning of the 1960s has the NHS received such large real increases in funding.

But while few would disagree with spending more on the NHS (opposition leader William Hague? The private medical sector? Devotees of the public health model? ) there are some questions and issues that need clarification.

What is the problem the extra money is meant to solve (apart from the tautological answer of underfunding)? More money will mean more healthcare which will mean more health. Does this mean that by the end of the next parliament the winter crisis will be a thing of the past, that there will be no more bad press for the NHS?

This is unlikely: Canada spends 9.1 per cent of its GDP on healthcare and 'ER crunch', 'ER under pressure' and 'Boy's death prompts calls for health reform' were typical headlines this winter.

As we spend more on the NHS our expectations of the service will undoubtedly rise to cancel out the very increase in the level of service the extra funding will provide. This is not an argument against increased funding. But ignoring a basic economic fact will only lead to disappointment in the long run.

And in the long run, if we don't want the NHS to lurch from one crisis to the next, what we have to address is the lack of proper mechanisms and institutions to create an acceptable equilibrium between our individual expectations and the economic realities of a collectively funded healthcare system with a finite budget.