Home Swede home? It's not an ideal family scene, Mr Cameron

IF ANYONE believes the sex war is over, look at the weekend's headlines – for once double standards are not the sole preserve of men. Iris Robinson is not a sinner according to a Times columnist, who argues that any middle-aged woman who can shock the grim, grey-suited orthodoxy of Northern Ireland by seeking sexual satisfaction deserves canonisation.

On the other hand, here in golf-crazy Sweden, Tiger Woods's proposed 1.8 million donation to the Haiti relief appeal hasn't dented fury over his serial infidelity to Swedish wife Elin, with the normally pacifist Aftonbladet commending her vengeful golf strokes.

"While Hillary and Posh Spice chose to keep silent, diet and become feminist doormats, Elin stood with both feet firmly planted on the ground and realised the shame was Tiger's, not hers," it wrote. "Thank God for girls like Elin. Next time, I hope she uses a bigger club."

Iris is a saint (because few warm to her righteous-sounding husband). Tiger is a sinner (because everyone warms to his beautiful, serene-looking wife).

So much for rationality in the torrid world of sex, infidelity and marriage, and yet that is the uncertain world into which David Cameron has plunged the Conservatives with his on-off pledge to encourage marriage by tax breaks.

Cameron says evidence shows a married, two-parent family is the best way to bring up kids. Maybe it is. But if a lifelong, monogamous, formally recognised and legally binding commitment is unattainable for a sizeable minority of Britons, making marriage the gold standard will fail, and the creation of more single-parent families may be the unintentional result.

Sweden has the second-highest divorce rate in the world – second only to the family-loving United States. But there is an important distinction between the countries and one that ought to interest shadow chancellor George "I watch Wallander" Osborne as he cosies up to Sweden's ruling Moderates.

In the moralistic US, children are three times more likely to be born to young, uneducated single mothers as they are in progressive Sweden, where unmarried couples are almost the norm and solo teenage mums are almost unheard of. American society has praised marriage, made an industry of divorce and made "living in sin" as unacceptable as single parenthood. Is this how Cameron's Britain will turn out?

Healthy mums – married or unmarried – also tend to be young mums, but in traditional societies without universal, affordable childcare that option not only takes women out of the labour market for ten years, but shatters the motivation of young women, educated to become useful members of the workforce, not primarily mothers. Few talented girls leave school itching to have marriage and kids, rather than jobs. Just as well, because few young men are itching to make permanent life choices or become young fathers either.

If more, happier children with younger parents is the outcome politicians really want, they would do well to look at the problem differently. The birthrate in most of northern Europe is positively glacial – but in Sweden it has risen when tax concessions have been made to working parents and declined when budget cuts have removed them.

A two-parent, married family may be the most stable child-rearing unit, but bidey-in cultures like Sweden – along with the rest of Scandinavia – seem to produce happier, healthier children than societies that revere marriage but then fail to make it work.

If Sweden really is David Cameron's template, he should note that a culture of successful co-habitation doesn't flow from marital tax perks – on the contrary, all income tax in Sweden is levied individually, even on husband and wife.

Nordic "patchwork" families operate well, because there's little stigma attached to leaving unhappy relationships. Some commentators suggest this is the legacy of Viking times, when men spent long periods away and women had other relationships. Whatever the reason, there is an automatic understanding that when relationships break down custody will be shared, parents and grandparents will rally round and the separating couple will continue to have a civilised relationship.

This is perhaps less good than marriage as it used to exist in Europe, but better than having exalted beliefs in formal lifelong partnerships that end up falling apart. Happiness is generally less common among people who want what they cannot have. So if the dream of living with one man or woman for life won't work, we are promoting it at our collective, emotional peril.

Downgrading the social acceptability of less permanent, but more viable arrangements creates a slippery slope with two fixed points – the "top" inhabited by lifelong, married couples and the "bottom" inhabited by deprived, single young mothers. Most of us live somewhere in-between – bidey-ins, singletons, second marriages, widows, unrecognised and unsupported pioneers making up the rules up as we go along.

If Mr Cameron wants stable relationships, happy children, younger parents and votes from suspicious modern Scots, he should use the general election spotlight to embrace Swedish-style childcare, not US-style marriage, and adjust policy to favour working parents.

First, MPs could ensure that their own pensions – which allow claims by co-habiting partners – extend to voters.

Second, they could put the housing market in order to avoid an entire generation becoming commitment-phobic – preferring single life in their parents' home to any "joint" arrangement.

Third, they could create a climate that supports full employment in productive jobs, since the biggest threat to marriage appears to be unemployment – according to David Webster, of Glasgow University, unemployed men are seen as less attractive as marital propositions.

And finally, if there is not to be a Nordic childcare revolution, a little humility please.

The last time Tories banged on about marriage, they were generally more involved with their secretaries.