All cities have now become salesmen for themselves. They are all equipped with "directors of regeneration" who would be better described as directors of self- advertisement. The brochures speak of "challenges" and "opportunities", in the standard lingo of business schools. The local labour force is always "skilled", and the investment is always "inward".
Many commentators buy all this. In London they look at the loft life of Clerkenwell or the scaffolding outside the new Museum of Modern Art at Bankside. In Manchester they sample the restaurant life of Castlefields. In Newcastle they ogle the Saturday night-time clubbers. They then announce that the big turnaround has arrived. The decline is over. We are in the presence of an urban renaissance.
But the revival of the inner cities is almost entirely mythical, and the danger is that we shall once again base public policies on false perceptions. Later this month, the government's urban task force, chaired by Richard Rogers, is due to report. Its brief sprang from the panic generated by forecasts (which have since been questioned) about how many houses we shall soon need, and from the conviction that we should force as many of them as possible to be built within existing cities. Yet we are still living with the debris left behind by previous schemes to funnel people into places they wouldn't otherwise have gone.
Even where huge sums of money have been spent on rescue attempts - as at the notorious Broadwater Farm Estate in Tottenham, north London - you need only go there to see that it is a high-wire act. The smallest slip, and things will be back at the bottom.
We have to learn from the history of urban design. Many of these mistakes sprang from architects' and planners' hostility toward suburbia. For many writers, "suburban" is the worst insult imaginable. Yet it is a form of self-hatred or, worse still, snobbery. Most people either live in a suburb or grew up in one. About a third of the British population lives in a semi. The architectural historian Andrew Saint attacks "the relentless puffing of metropolitan life and culture". He calls it "unbalanced - lazy, even". In defence of the pleasures of suburbia, he argues that "the belief that we must all be crammed into dense communities and deprived of our cars . . . is apocalyptic and improbable".
Behind the merry talk of regeneration, local councils are often at their wits' end. I was at a seminar recently, at Goldsmiths College, London, on whether there was a Third Way in local government. "Housing" - which used to be seen as the core activity of local, and sometimes central, government - was a word not mentioned by anyone from the platform or the floor, from beginning to end. Later a former council leader (Labour) told me why: "Everyone knows it's a disaster. But no one knows what to do about it." A fortnight later the director of a right-wing think-tank gave me the same reason for not publishing pamphlets on housing.
When you are in a hole, the first thing is to stop digging. So we should stop trying to press people into urban spaces they don't want to occupy. The estates now seen as such disasters were usually put up because of a dogged wish to introduce something more "urban" in form - either the towers of Hackney's Nightingale Estate or the tightly packed low-rise of Islington's Marquess Estate. Both are being expensively torn down.
Going around England, I look at some of the so-called urban villages pushed into odd corners of towns and I wonder whether we are not just creating future slums. Not on the same scale as Hulme in Manchester, all 350 acres of it, now being redeveloped for the second time in 30 years - but slums all the same. Houses that are built too tight for most people's needs in the late 20th and early 21st century. And built, often, in the wrong place. They are where they are only because it is easy to get planning permission for a "brownfield" site. (Like most jargon, this is a word to be wary of: it includes former playing fields.) One of the linguistic triumphs of ecology and sustainability is the rhetorical contrast between greenfield (sacred) and brownfield (profane).
So there is no inner-city revival. What is happening is that a few city centres, especially those on the tourist trail, are being transformed into a kind of urban theme park: London certainly, Edinburgh probably. A place to have a good time in; a theatrical shell city. And offering only certain sorts of (mostly poorly paid) jobs.
It used not to be so. Once, city centres, and the fringes of the centres, were awash with modest full-time jobs. Until 1961 Carreras had a huge art deco cigarette factory in the middle of Camden Town. Then planners told such firms to move out, and Carreras (now part of Rothmans) went off to Basildon New Town, taking the jobs with it.
In an important new study, Ivan Turok and Nicola Edge, of Glasgow University, examined employment trends in the 20 largest British cities. These ranged from conurbations such as Greater London and Merseyside to free-standing cities like Bristol, Sunderland and Nottingham. Together they account for two-fifths of Britain's population and jobs. Since 1981, Turok and Edge found, these cities have lost half a million jobs; the rest of the country gained 1.7 million. They argue that the drift of jobs away from the city, towards small towns and rural areas (which generally means suburbs or suburbanised villages), "shows little sign of having abated or being reversed in recent years". The much-hyped services sector has expanded almost everywhere - but it expanded least in the conurbations.
It was the years 1993-96 that started the talk about an urban renaissance, because at that time the number of jobs in cities rose. But as Turok and Edge point out, employment was then rising everywhere. The cities' share of national employment actually fell. For London the contrast is especially striking. Between 1981 and 1996, Greater London lost 212,000 jobs. The rest of the South-east gained 556,000.
Many of the jobs gained, everywhere, were part-time jobs taken by women. In the ten years from 1981 to 1991, Turok and Edge report, the great conurbations and the big cities lost almost a fifth of their manual jobs (mostly male). They gained some professional jobs, but few people made the upward shift. Instead they slid down. The decline in skilled manual work forced many men down into less skilled, worse paid and casual jobs. Which leaves even fewer jobs for those lower down the pile.
And so those people who can move out do. Visiting Hackney housing estates - trying to pull themselves up by their bootstraps after decades of council mismanagement - I am struck by the way they have been abandoned by younger, more ambitious people. This isn't just due to ludicrous allocation policies which pack the most vulnerable together. Nor can you blame it on Thatcher's right to buy, which hardly impinged on London's multitudinous blocks of council flats.
The point is a psychological one. Anyone with any go will go. Suburbia, and little towns just across the green belt, offer more jobs, more living space, better schools. And the greatest of this trinity is jobs. Turok and Edge are sceptical about the present approach to cutting unemployment in cities. "Many policies misdiagnose urban unemployment as caused by inadequate skills and motivation, rather than a lack of jobs."
Cities are becoming hollow to the core. London is gradually dividing into a city of two classes - the professionals and the poor. Of two ages, also: younger in the centre; older further out. The middle is disappearing. Technicians, secretaries, computer operators and what used to be called the respectable working class: these have taken their leave.
Once a tide starts to flow, it is very hard to stop. You have only to walk along the South Bank, past the new Globe, to see that it's nearly all a tourist-trade operation. Many buildings are as thin, architecturally, as stage sets. This will not bring much joy to the semi-derelict heartland of Peckham. Nor is new transport always the answer. With the Jubilee Line and Docklands Light Railway extensions, the people of unemployment-plagued Greenwich may be better supplied with trains. But it will now also be easier for outsiders with specialist skills to catch a train in and compete with locals for the better jobs.
In London we have no examples yet of the kind of urban abandonment and dereliction you get throughout America. This is partly because it is a long-established capital city with many complex interweavings of residence and employment. No single city in the US combines all London's functions in government, media, education and the arts. This is one advantage of the much-derided centralisation of power and influence.
But this good news distracts attention from what is happening elsewhere. Look beyond London, and the picture is much greyer. Read The Slow Death of Great Cities?, by Anne Power and Katharine Mumford (newly published by the Joseph Rowntree Foundation). The title evokes Jane Jacobs' classic 1961 onslaught on misdirected planning, The Death and Life of Great American Cities. Power and Mumford tell the story of the south Bronx in its potentially ominous British version.
They studied four inner-city neighbourhoods in Manchester and Newcastle. Their findings chronicle an urban disaster, a firestorm of dereliction. Homes are being abandoned: good, modernised ones, as well as bad, and private as well as public. House prices fall, sometimes to zero. Streets and blocks are demolished 20 years after the last Labour government announced it had "pensioned off the bulldozer". Power and Mumford print a photograph of a housing association sheltered scheme, not yet ten years old - two storeys, traditional style - which is due to be pulled down. Other photographs show boarded-up shops and streets where every other house has metal screens over it because the inhabitants have left and no one wants to come in. "The speed with which streets or blocks are shifting from being relatively well occupied to nearly half-empty is alarming," the authors write.
This, they argue, is the end product of previous Whitehall and town hall attempts at Utopian solutions. "Aneurin Bevan's dream [when he was the postwar housing minister] of creating English and Welsh villages was corrupted into large, monolithic, single-tenure, single-class estates." These "colossal and costly projects blighted every major inner city in Britain". The blight often lasted 30 years or more. Councils plunged on, even though Jane Jacobs, in America, and Michael Young and Peter Willmott, in Britain (in 1957), had already raised the alarm.
In his revisionist gospel The Future of Socialism, Anthony Crosland mocked the right-wing press for continuing to argue for houses and gardens instead of blocks of flats. But doctrinaire anti-suburban policies destroyed "not only many established communities, but also many jobs and services", Power and Mumford state.
Mostly it was Labour politicians, destroying the lives of Labour voters. "The idea that people could be re-ordered out of slums into new estates did not work." But, undeniably, the administrators who did this thought they were doing the right thing. Theirs was a conventional wisdom. They had absorbed it in different circumstances, 20 years before they reached the seats of power from which they could act. We must bear in mind now, even more forcefully, that our own conventional wisdom may be just as wrong. The design of a house, even its tenure and its precise location, matter far less than its adaptability to change, a spirit of neighbourliness and, above all, as Turok and Edge emphasise, access to work.
In spite of all the fiscal bribes, the old way of work is drifting away from north to south. Countryside pressure groups wring their hands about the threats to southern England's green fields. But as jobs move, so does the countryside. Soon County Durham will be nothing but green fields. Oliver Goldsmith wrote his poem "The Deserted Village" as the industries of the north pulled prosperity away from other parts. The pull is now the other way round. Houses have always followed work. Today's conventional wisdom risks thinking that if we build houses in the ecologically correct place, all will be well. But, without jobs, it won't.
The real way cities grow is through the multiplication of suburbs. Americans call it "edge city". We should learn from the disastrous record of government intervention in relocating industry. Attempts to go against the flow always fail. (The bribed economy of "inward investment" by foreign firms will also fail.) If people wish, for perfectly good reasons, to live out of cities, they should not be deterred.
We should be wary of the prediction business. The hopeless inability of a firm as big as BT to predict telecommunication usage in London these past ten years is a timely warning. But as far as we can tell, the new urban future will be a vigorous edge-city outer ring, with a shell city within. It is hopeless, and counterproductive, to try to stop edge city in its tracks. The real task is to make shell city humane.
The writer is a senior fellow of the Institute of Community Studies. This essay draws on his paper in the summer issue of the "Journal of Design History"