If our politicians are to be believed we have the best armed forces in the world, the best firefighters, the most talented young people, the best farmers, the most effective democracy and so much more besides. How blessed are we to live in such a land of superlative achievements, such talented people, such enviable institutions.

Politicians the world over do the same, using cynical rhetorical devices to persuade some interest group or other that they are loved, or to reassure the public how wonderful everything is. But the one thing all British politicians fall over themselves to assert is that we have the best health service in the world. It seems almost impossible to mention the NHS without saying so. They then almost invariably go on to point out how dreadful the American system is by comparison.

This is dangerous. The evidence just does not support the contention that we have the best health service. Suggesting we run healthcare better than anyone else because we do it better than the Americans is rather like saying we have the best parliamentary democracy in the world because we do things better than the North Koreans. Other models are available.

Here is the first headline finding from the OECD’s most recent set of international comparisons: “While access to care is good, the quality of care in the United Kingdom is uneven and continues to lag behind that in many other OECD countries”. That is borne out across a wide range of measures. Overall life expectancy is no more than middling. We are in the bottom third of comparable countries for cancer survival rates and in the middle third for strokes and heart attacks. In an understatement of which we British might be proud, this Paris-based organisation concludes “the UK does not excel at providing high-quality acute care”.

This is not because we have healthcare professionals who are any less dedicated than those in other countries. We do not lack will, effort, compassion. And of course we do some things well. Survival rates from cancers, strokes and heart attacks are improving, albeit from a low base. Our performance on breast and cervical screening as well as vaccination is better than most. And on many measures of efficiency, such as spending on drugs and length of hospital stays, we perform well. Yet for all that dedication and compassion, for a wealthy nation we have no more than a fair to middling health system. Some bits are good, many much less so.

As recent work from the Health Foundation and Nuffield Trust has shown, this is not because we spend much less than others on health. Across developed nations as a whole, and against wealthy EU nations, we spend a perfectly respectable amount: somewhat less than the French, Germans and Dutch, rather more than the Spanish and Italians.

Spending more would surely help, especially after seven years of financial drought. We will need to increase funding further, probably by a lot as the population ages, expectations increase and costs go on rising. But our relatively poor performance on outcomes is not just down to how much we spend. Where the money comes from, and how it is spent, also matters.

Almost all the money comes from general tax revenues. This does have the great advantage of ensuring an equality of access which is good, though by no means unique, by international standards. Though don’t forget it does not ensure anything approaching equality of outcome; the rich still live a lot longer than the poor.

Reliance on this single source can cause problems. Taxes can be hard to raise and the system can become monolithic. Systems paid for through social insurance, like those in Germany and the Netherlands, have their own problems but do seem to adapt more quickly, and they are at least as redistributive as our own system; higher earners pay higher rates and the poorest get into the system for free. They also allow health and social care funding to be brought relatively easily together. The Germans simply added a long-term care insurance fund to their health insurance system. That doesn’t get round the need to pay but it does avoid the huge inefficiencies and inequities created by our system of free, tax-funded healthcare alongside severely means-tested access to social care. We tend to forget this Cinderella element of our overall system when singing the praises of the NHS.

Our inability to do anything about it, exemplified by the aborted proposals on social care during the election, is just one part of the wider problem of the infantilisation of public debate. The whole system is inconceivably complex. However much we might want them, simple solutions are not available. You can’t just run healthcare from Whitehall any more than you can do the same for manufacturing industry. It is so big and complex that it forms a whole sector of the economy as much as it does a public service. Like any successful sector it needs to adapt and learn from the best in the world.

For that to happen we need to call out our political overlords when they shower us with drivel about how very lucky we are to live in the best of all possible worlds. Free universal healthcare is a precious thing indeed. To protect it we need to stop worshipping at the shrine of the NHS and stop demanding it be preserved in aspic. We need instead to ask how it can change for the better.

This article was first published by The Times and is reproduced here in full with permission. Paul Johnson is director of the Institute for Fiscal Studies. Follow him on @PJTheEconomist