Three centuries on, the state once known as Great Britain is on the verge of breakup, and some are cheering at the prospect of a truly postimperial age for Blighty.

In a Financial Times column this week, economist John Kay argues that Scots supposedly clamoring for independence are a fickle bunch—not motivated by any sense of national pride—and concerned only with very small economic interests:

[T]he Scottish Social Attitudes survey asked what respondents would think about independence for Scotland if it would make them £500 a year better off. They favoured separation by 65 per cent to 24 per cent. If independence would make them £500 a year worse off, however, it would be rejected by 66 per cent to 21 per cent. Yet £500 is less than 2 per cent of average Scottish household income.

For Kay and his pals in London, £500 may sound like a small sum, but consider that the gross weekly wage of the average Scot is £592.70. And when presented with the option for short-term gain apart from any detailed explanation of long-term consequences, it's no surprise that most would act in their perceived interest.

Yet Kay manipulates this data point to extrapolate all kinds of big claims about the decline of nationalism. "[M]ost Scots do not see the constitutional status of Scotland as integral to their identity or self-worth. . . . The modern state is an economic agent, not a coercive power, and is principally concerned with the best means of providing health and education, resolving international trade disputes and reining in global finance, clearing the rubbish and tending the parks."

Kay is heartened by the replacement of the British Empire with a nanny state, but he fails to see that this change resulted in a serious identity crisis for average Scots. It's in part caused by the failure of leaders in London to effectively define a new national interest for the whole of Britain—and has created an opening for small-time nationalists north of the border. An analysis that misses this larger dynamic is flawed.