‘Urbanization’ doesn’t capture very much of what cities are up to
(This post is basically a pre-emptive footnote. Please feel even freer to ignore it than you usually would.)
The principal topic of Urban Future is the development of cities (with Shanghai as exemplary case). It is peculiarly frustrating, therefore, to find that no single term exists to describe a process that is arguably the most important of all social phenomena, and even the key to whatever meaning might be discoverable in human history.
One thing, at least, is clear (or should be): urban development is not urbanization.
‘Urbanization’ is a comparatively rigorous and well-defined demographic concept, referring to the dynamic re-distribution of populations from non-urban to urban existence. Because it describes the proportion of city-dwellers within a population, it can be quantified by a percentage, which sets a strict mathematical limit to the process (asymptotic to 100% urbanized). When plotted historically, the approach to this limit follows a steep curve, echoing the (open-ended) exponential or super-exponential trends of modernization and industrialization.
Whilst theoretically indispensable, clear, meaningful, and informative, the concept of urbanization is inadequate to the phenomenon of urban development. Cities are essentially concentrational, or intensive. They are defined by social density, uneven distribution, or demographic negative entropy. Urbanization describes only a part of this.
Within the entire demographic system, urbanization provides a measure of the urban fraction (based on an at least semi-arbitrary definition of a city, by size and by boundary). It says nothing about the pattern of cities: how numerous they are, how they differ in relative scale, how fast larger cities grow compared to smaller ones, or in general whether the urbanized population is becoming more or less homogeneously distributed between cities. In fact, it tells us nothing at all about the distribution of the urbanized population, except that it is somehow clumped into ‘city-scale’ agglomerations.
Once ‘clumped’ – or drawn within the spatial threshold of a city-sized cloud – a demographic particle switches binary identity, from non-urbanized to urbanized. Registered as a city-dweller, there is no more to be said about it. Yet the city is itself a distribution, of variable density, or heterogeneous concentration. Within each city, urban intensity can rise or fall, irrespective of the overall level of urbanization. The limit of urbanization sets no restriction upon trends to urban intensification, as exemplified by high-rise architecture.
Urbanization is a proportional concept, indifferent to absolute demographic scale. In contrast, measuring intensity, or negative entropy, provides fine-grained information that rises with the size of the system considered (since the entropy measure is a logarithmic function of system scale, defined by the totality of possible distributions, which rises exponentially with population). Whilst social scientific or demographic phenomena are highly intractable to quantitative intensive analysis, their reality is nevertheless intensive, which is to say: determined by distributive variation of absolute magnitudes. The measure of urbanization is not affected by the doubling of a city’s population unless the overall population grows at a lower rate. Urban intensity, in contrast, is highly sensitive to absolute demographic fluctuation (and not uncommonly hyper-sensitive).
Intensities are characterized by transition thresholds. As they rise and fall, they cross ‘singularities’ or ‘phase transitions’ that mark a change in nature. A small change in intensive magnitude can trigger a catastrophic change in system behavior, with the emergence of previously undisclosed properties. When measuring urbanization, a city is a city is a city. As an intensive concentration, however, a city is an essentially variable real individual, passing through thresholds as it grows, innovating unprecedented behaviors, and thus becoming something ‘qualitatively’ new.
Whilst summoning the courage to float an adequate neologism (‘urbanomy’?), Urban Future will stumble onwards with awkward compounds such as ‘urban development’, ‘urban intensification’, ‘urban condensation’, or whatever seems least painful at the time (whilst meaning, in each case, what ‘urbanization’ would describe if urbanists had managed to grab it before the demographers did).
Yet, despite this linguistic obstacle, a surprising amount can be said about the urban process in general. Making a start on that comes next.