The word 'spectral', Lefebvre reminds us, has a dual meaning. It signifies, on the one hand, the influence of the dead over the living, and, on the other, a prismatic analysis, able to decompose a beam of light into its constituent frequencies. Through the prism of the spatial dialectic, the postmodern focus on the presence of the past illuminated a 'blind field' in the critique of urban space. If the practice of architecture abandoned its claim upon the process of modernisation, then what was assuming control over modernity's form? What the spatial dialectic proposed was a close investigation of the relationship between the spatialisation of capital and the capitalisation of space, since at the interface between the geography of accumulation and land speculation it was possible to recognise a social transmutation of the urban power of real estate.

Of course, the investigation into the relationship between the financial circulation of capital, real estate speculation and urban architecture was hardly new. From Louis Sullivan through to Le Corbusier, the ideologists of modernity had always comprehended the authority that money capital had over the production of urban form. What was at stake, Lefebvre argued, was the manner in which the separation of the different strata of social, economic and political decision-making appeared to become compressed through an intensification of the power of urban speculation – with an extensive concentration of political power in urban centres of global decision-making leveraged by an intensifying centralisation of financial and commercial capital in metropolitan real estate. Squeezed between global forces of centralisation and concentration, the space of everyday life took on a new ideological significance – what Jameson called a new 'cultural logic'. What then was the operating system which, under capitalism's new mode of planetary abstraction, gave culture a new spatial logic?

The answer lay, as David Harvey and Lata Chaterjee demonstrated in their brilliant 1974 analysis of the Baltimore housing system, in a financial intensification of the capitalist power to extract absolute rent from the monopolies imposed on the social totality. 'Absolute rent implies class monopoly power of some sort. By a 'class monopoly' we mean a class of producers (or consumers) who have power over a class of consumers (or producers) in a situation of structured scarcity.' [1]The purest historical form of this power to structure scarcity arises in the form of landed property. 'Landed property,' Marx said in the third volume of Capital, 'presupposes that certain persons enjoy the monopoly of disposing of particular portions of the globe as exclusive spheres of their private will to the exclusion of all others.' [2]

What fascinated Marx was that, although landed property acted as a geographical barrier to the mobility of capital, the historical development of capitalism tended to conserve rather than abolish rent-seeking institutions (like land owners and financial speculators). The reason why, Harvey and Chaterjee pointed out, was that landed property formed a social infrastructure and 'decision environment' which preserved capitalism's structural integrity even when constantly subject to socio-technical transformations and financial crises of its own making. An analysis of absolute rent therefore provided a way to follow the motion of capital, tracking a space of conflict internal to the capitalist class where the agents of rent, interest and profit fought for the spoils of exploitation arising from the various kinds of human and environmental crises created by a market society (poverty, disease, pollution, famine, homelessness etc.).

The theory of rent is one of the most complex and overlooked areas of Marx's critique of political economy, but its value lies in illuminating the 'historically specific ways in which landed property influences the pace, rhythm and direction of capital accumulation'.[3] Moreover, the category of absolute rent is able to shed light on another dimension of capital: the seemingly miraculous ability of capital to convert things which are not of the market into money like commodities. There was, Marx suggested, something peculiar about the absolute rent which the owners of landed property command from the commonwealth of society, which makes it equivalent in form to a pure financial profit. 'The price of land' becomes nothing more than the capitalisation of future income 'and thus anticipated rent';[4] and in doing so, the financial capitalisation of land provides a means of comparing money capital, like stocks and bonds, with real estate. Rent, therefore, manifests an economic power of conversion, the transformation of a stock of land – whether in the context of agriculture, oil or 'urban regeneration'[5] – into a flow of money. Or to put it another way, absolute rent can convert all that is spatial into income.