'Equal pay now! Equal pay now!", the chant echoed up to my hotel window in Oslo, as strikers and their supporters marched past the Norwegian parliament. How could this be? Are there strikes even in paradise?

By most comparative measures, <a href="http://www.theguardian.com/world/norway" title="<00ad>Norway">Norway is something close to a paradise on Earth. Per head of population, it is one of the world's richest countries. It is also one of the most equal. It has a welfare state that is the envy of social democrats everywhere. Mothers get 10 months' maternity leave on full pay. Last year, the country led the world in the well-respected human development index, which combines measures of life expectancy, literacy and standard of living. Norway is free, rich, peaceful, safe, healthy and, so far as anyone can measure these things, happy. Oh yes, and in these times of fiscal hardship, it has a budget surplus of more than 9%. And it gives more than 1% of its gross national income in overseas aid; so it's virtuous, too.

No wonder all sorts of people cite it as proof of all sorts of things. Conservative Eurosceptics like MEP Daniel Hannan and the newly elected, aptly named, MP Mark Reckless hold it up as an example of how well Britain could do if it left the European Union. "Sovereignty evidently suits the Norwegians," Hannan wrote a few years ago, suggesting that Britain could fare equally well if it joined Norway in a free-trade area linked to but not part of the EU. How wise the Norwegians were to vote no to EU membership in two referendums, in 1972 and again in 1994. If only we had voted no, we too might be as rich, safe, healthy and happy as they are.

For Richard Wilkinson and Kate Pickett, by contrast, Norway is an example of the benign effects of equality. In their influential book The Spirit Level: Why More Equal Societies Almost Always do Better, they several times cite Norway, along with other Scandinavian countries, to illustrate the many good things that come with greater equality: welfare provision, fewer teenage pregnancies, high levels of literacy and social trust. "In Norway," they write, "it is not unusual to see cafes with tables and chairs on the pavement and blankets left out for people to use if they feel chilly while having a coffee. Nobody worries about customers or passers-by stealing the blankets."

"Humbug," cry others. The key to all this is simply oil. The whole egalitarian social democratic model is actually sustained by the country's vast exports of oil and gas, the revenues from which it has been stashing away into what is now the world's second largest sovereign wealth fund. With a value of around £300bn, that will be more than adequate to keep the country's fewer than 5 million people in the pampered social democratic manner to which they are accustomed. If the fund goes on growing as it has been, it will even – uniquely in Europe – almost cover the future pension obligations for an ageing population. So, according to these hard-nosed hydrocarbonists, the only way you can continue to enjoy such an old old-fashioned statist model of social democracy is to "drill, baby, drill". Norwegian happiness is, to so speak, paid for by global warming.

Or then again, perhaps the key to Norway's success is just being, well, Norwegian. Maybe it is their unique traditions of sturdy self-reliance, hard work and community pulling together, celebrated in history and legend, with imaginative reference back to the Vikings. After all, the country was doing quite well with its exports of fish, timber and manufactured goods, and its shipping industry, even before it struck oil in the 1960s. Marvelling at the functional beauty of the Viking ships in the Oslo museum, it is easy enough to imagine a narrative of successful national exceptionalism. The Scandinavian Airlines plane on which we flew back from Oslo was called The Peaceful Viking.

I know far too little about Norway to judge what is true or false in any of these versions – and what is missing from all of them. But Norway – or perhaps I should say "Norway" – is a good illustration of the danger of drawing too-simple lessons from the experience of other countries, or of projecting on to them lessons you want to draw for your own. Norway is outside the EU, Norway is rich and happy; ergo, leave the EU, and you, too, will be rich and happy. Often you end up falling into the old fallacy of confusing correlation with cause.

Some years ago, people argued for a big expansion of the number of students in higher education in Britain. They pointed to Germany. It had more students in higher education, they said; Germany was doing well economically. But the sheer number of students in higher education had very little to do with Germany's economic success. The spread of the Massenuni, the mass university, did however have quite a lot to do with the way Germany's universities were sliding down the international league tables, and actually impelled some of their brightest students to come and study in Britain. What Britain should have emulated was Germany's historic focus on high standards of technical education, at all levels. That does help to explain why Germany continues to make things – whether cars, dishwashers or machine tools – that other people want to buy. So the point is not that you can't learn from other countries' experience. The point is to learn the right lessons.

Even then, you need a detailed, granular understanding of how any particular tool or element will fit into your own national mix. Charter schools in New York may have something to teach those who wish to develop academies in London, but the context is very different. By the time it reached eastern Europe, the privatisation pioneered by Margaret Thatcher resulted in the empowerment of old communists – not what she had in mind at all.

While I was thinking about these traps of translation or imitation, another demonstration pulled up under my Oslo hotel window, also on its way to the parliament. It was much smaller and messier, without the union stewards, and at first I couldn't catch the chant. Then I made it out: "Boycott Israel, Free Palestina!" The night before, Israel had attacked the aid flotilla to Gaza. So far as I could see, the police turned up only after the demonstration had moved on.

So even distant, fortunate Norway is not entirely immune from the shockwaves of world politics. It has struggled, like most European countries, to integrate its growing population of Muslim faith or origin. It depends on European markets to take its exports. Its massive national pension fund has to be invested somewhere, so it also depends on the performance of global stock markets.

If things go really pear-shaped in the rest of Europe, Norway may yet face a reverse wave of modern Vikings – "peaceful Vikings", to be sure – coming to look for work and welfare on those happier northern shores. I'm told EU citizens can go and live in Norway for up to three months while job-hunting. Tempted, anyone?