The geographer Saskia Sassen is one of the sharpest analysts of the detail of globalisation – and I was able to see her speak on Thursday evening in London at an event organised by the RIBA ‘Building Futures’ programme. (I’ve posted before on her analysis of how different parts of government gain or lose from globalisation).

Her talk was based on a big academic study in which she and her researchers ranked 63 leading cities – cities, in her terminology, with a ‘global city function’ – by a whole set of criteria. Different cities came top on different assessments; Vancouver, for example, was top on the criteria of “ease of doing business”. Her conclusion from this is that the global economy extracts value from the (often small) differences between cities – but the small differences are critical to the value which any particular city creates.

A couple of examples: it was said, before China regained control of Hong Kong, that their financial services centres would be in competition with each other. It turns out that Hong Kong is the international financial centre for China, while Shanghai is the national financial centre. (It could be said that there’s a comparable difference in the UK between London and Edinburgh). Within the US, again in the financial sector, Chicago is the centre for commodities futures, while New York is the centre for futures on interest rates. And the Chicago story tells us something else: that often these small differences are rooted in specific material histories. Chicago is a centre for commodity futures because of its history as the meatpacking and food processing centre for the mid-west.

Along with “specialised difference” goes “inhabited infrastructure” – although the buildings, from the airport to the office complexes to the hotels, may seem very similar no matter where you are, the way they are used is different. And it’s in the use that value emerges. There’s a summary of Sassen’s argument here, written for a different event (opens in pdf).

This argument was a relief to me, since I’d chaired a session earlier in the day in which Reinier de Graaf of OMA and Ayona Datta of the London School of Economics had discussed ‘people and planning’, and talked about ‘mobilities’ (and who is mobile and to what end). de Graaf is incisive on the subject of Dubai, and Datta ‘s talk looked at both the Turkish global elite in Smyrna and Polish service workers in London. By the end of the session, we’d got to a depressing place: that if the markets for buildings and cities were constructed largely by global elites, cities ended up as a grim triangle between housing high value “creative” or “knowledge” businesses, and workers, providing their entertainment and leisure “experiences”, and accommodating the service workers who migrated (as often as not) to support these. Thank goodness for the subtleties of differentiation and use.

Earlier in the evening discussion, Spencer de Grey, of Foster’s, had addressed the theme of ‘globalism and localism’ with an impressive presentation – almost a global tour – of Foster buildings and developments which were sensitive to local terrain, local climate, local history, local materials, and local cultural traditions, which partly begged the question of why local developers sought out global architectural practices. (He didn’t, by the way, mention the rather unimpressive Foster production that I work in in London). One perspective came from the floor from the architect Robert Adam. He argued that what clients are buying, when they buy from an anglophone global practice (and 80% of the global architecture practices are anglophone), is an association with the global market, which was, he suggested, effectively a ‘North Atlantic’ construction going all the way back to Bretton Woods.

Which may also explain, as my colleague Joe Ballantyne argued recently on the Henley Centre HeadlightVision blog, why British and American commentators seemed to be blind to the many signs that the current wave of globalisation had reached its peak: they were too immersed in it to see the signs.

My own view, at least on the architecture boom, is that it’s a by-product of the 20-year boom caused by cheap capital and minimal financial regulation that is disappearing with the credit crunch. In twenty five years time we’re likely to look back on the years from the mid-80s to the mid-00s with amazement. Doubtless architects will still be working internationally (because they have done for at least four hundred years); but they won’t be working, at least not often, on things which are intended mainly as statements of commercial and cultural bragaddacio.