Leading Article: Nice idea, Mr Brown, but where are these jobs coming from?

Like the tides, if not quite as regularly, capitalist economies like ours have swung from boom to bust.

Economists say there are signs that the distance from peak to trough may be lessening, but their continuing existence is not in doubt. The Chancellor of the Exchequer may this week be walking on water, but it can confidently be asserted that within the next few years the British economy will turn downwards and unemployment rates will turn up. Who then will collect their P45s first? The test of Gordon Brown as an effective politician - in his own terms - then arrives. If the first out are the young with marginal skills, those living on estates in Merseyside, Manchester or Peckham, older men and young black men, then all his impassioned rhetoric yesterday about social justice and opportunity for all will sound dreadfully hollow.

Perhaps Mr Brown does believe that 200 years of economic history came to an end on 1 May; that his invocations of the long-term view, together with his skills as a macro-economic manager, will guarantee stability and the abolition of the economic cycle. Even so, to redeem his high- flown promises to the excluded and the unemployed he will have to perform the amazing feat not just of seeing employment grow while the economy is booming, but to continue to see jobs created even when it dips. That commitment to turn the welfare state into a "platform" for work was well made, and the measures announced by Labour so far are a plausible mixture of sticks and carrots. The Government, he said, in a phrase which demonstrates the distance Labour has travelled in recent years, cannot prevent people losing their jobs, but can assist them to get the next one.

But if you are saying to the unemployed, "the age of exclusion is over", you are committing the state to ensuring that demand remains high in an age when Keynesian tools have been discarded. Perhaps Labour is confident that it can guarantee that British business will deliver the jobs on which the expansion of opportunity depends. Perhaps Mr Brown has a plan for conjuring jobs out of the public sector while reducing the national debt. Either way, he did not dilate upon method yesterday, except - unknowingly? - in mentioning ways in which employment might be reduced. If British business is, as he promised, made more competitive, is it not possible that jobs are cut?

The trouble is, Mr Brown also wants to alter the arithmetic of employment. It is not just a question of finding work for those who are unemployed now. His measures will surely also increase the supply of labour. Better child-care facilities - much needed, it is true - ought to mobilise women who are not now classified as jobless. The assault on definitions of disability and long-term sickness being prepared by Harriet Harman will also have the effect of redefining as employable large numbers who are not so classified. Reaching "full employment" may involve creating around 1 million more posts, but Labour is embarking on these other measures that may add hundreds of thousands of people to the labour pool.

Then there is the geography: where are those jobs going to be? In the south-east of England, in East Anglia and other growth regions, the response may be easy: already there are bottlenecks in the supply of labour. Skip over the (rather tricky) question of whether those unemployed can in fact be trained for available slots. What is the mechanism by which jobs are created in those regions, notably Merseyside and peripheral Glasgow, where unemployment remains high? Not a word yesterday about regional policies. Mr Brown was anxious to distance himself from the policy failures of the Wilson and Callaghan years, but he may find himself having to revisit their big-spending remedies for geographical exclusion.

Hubris is stalking the Brighton conference hall this week. Gordon Brown had, before the election, made the dampening of expectations his stock- in-trade. Yesterday he let rip. Popular, clever, charming the Chancellor of the Exchequer may be. He has certainly during the past week or so pulled off the amazing feat of appearing utterly convincing on the world stage at the International Monetary Fund while continuing to speak plausibly about domestic priorities for reducing income inequality. But sooner or later those delegates who currently sit so politely on New Labour benches will expect results on the employment front. They may even take Mr Brown at his word, which means he will inevitably be found wanting. The question is, by how much?