OVER three centuries the union between Scotland and England has survived skirmishes, rivalries and, last year, a nail-biting referendum. But increasingly, Scotland is its own country. It will soon decide its own income-tax levels and bands, control half the receipts from the VAT sales tax and set some welfare payments. The vote may be extended in Scottish elections to 16-year-olds (in England the voting age remains 18). After its near-clean sweep of Scotland on May 7th, the emboldened Scottish National Party is out for more. The SNP, which runs Scotland’s devolved government and now holds all but three of the Scottish seats in Westminster, has confronted David Cameron, the prime minister of the shaky union, with demands to set business taxes, the minimum wage and more aspects of welfare policy. Scotland, already semi-detached, would become an even more distant neighbour (see article).

Ye’ll take the high tax and I’ll take the low tax

For those, including this newspaper, who believe that Scots and their fellow Britons are better off together, it is tempting to resist such demands. Granting concessions to a party bent on leading its country into what looks like a less prosperous, more vulnerable future is risky. Some fear that further devolution would put Scotland on a one-way road to severance. For Mr Cameron, recently returned with a thin majority, it is an unappealing time to give ground to political rivals. Yet he should grant Scotland the freedoms the SNP’s leader, Nicola Sturgeon, demands—and more. Greater autonomy would lead to better, fairer government. It might even scotch demands for divorce.

Not all who voted for the SNP want independence, and its support is flattered by the first-past-the-post system, which awarded the party 95% of Scotland’s seats for its 50% of the vote. It will not achieve such a wipeout in elections next year to the Scottish Parliament, which uses a proportional system (and which the rest of Britain could learn from). Even so, the Nats’ crushing victory is a mandate for radical change.

And change would be welcome. Britain is suffocatingly centralised, and draining power from Westminster would do it good. There is no reason why the minimum wage should be the same in Lothian as in London, or why Scottish businesses should pay the same rates as those in England. Scots see themselves as more left-wing than the English; if they want a more generous welfare state they should be able to establish one.

But they should also have the responsibility to pay for it. That is why Mr Cameron should go further than Ms Sturgeon’s immediate demands, which combine autonomy with continued subsidy. A better solution would be to press ahead to full fiscal autonomy. It could cost Scotland around £8 billion ($12 billion) a year. But it would be fairer than the existing “Barnett formula”, a crude mechanism which lavishes English subsidy on Scotland while shortchanging poorer Wales. And it would force upon Scotland more grown-up politics. Decrying austerity, as the SNP has done so rousingly, is easier when the books are balanced in another country. Canada’s Parti Québécois shows how the appeal of populist separatist parties can fade once they win real power (see article).

There are three other reasons for straightening out Scotland’s relations with the union. They are called England, Wales and Northern Ireland, which are ever more fed up with their cobbled-together, inconsistent constitutional settlements. The English, in particular, resent the fact that all MPs vote on matters that affect only England, which lacks a parliament of its own. If it is to survive, the United Kingdom will have to look more like a federation. Giving Scotland real freedom—and with it real responsibility—should be the first step.