The science and politics of gentrification

I figured that, after the tribulations of touching on the sensitive subject of genes and behaviour, it might be some light relief to turn to the interesting subject of urban development, and specifically a new paper looking at the morphological characteristics shared by parts of London that have recently undergone gentrification. I was attracted to the study partly because the locales it considers are so familiar to me – two of the areas, Brixton and Telegraph Hill, are just down the road from me in southeast London. But this also presented an opportunity to talk about the emerging approach to urban theory that regards cities as having “natural histories” amenable to exploration using scientific tools and concepts that were developed to understand morphological change and growth in the natural world. It’s an approach that I believe is proving very fruitful in terms of understanding how and why cities evolve.

Well, so I fondly imagined as I wrote the piece below for the Guardian. Now, I’m not totally naïve – I realise that gentrification is a sensitive subject given the decidedly mixed nature of the results. Districts might become safer and more family-friendly, not to mention the fact that they serve better coffee; but at the same time they can become unaffordable to many locals, stripped of some of their traditional character, and prey to predatory developers.

I’ve seen this happen in my own area of East Dulwich. I always feel that, when I say to Londoners that this is where I live, I have to quickly explain that we moved here 20 years ago when properties were cheap and the main street was fairly run-down and populated by a mixture of quirky but decidedly un-chi-chi shops. There is no way we could afford to move here today. So yes, the parks and cafés are all very nice, but I’ve mixed feelings about the demographic shifts and I’m dismayed by the stupid property prices.

So it was no surprise to find such mixed feelings reflected in the readers’ comments on my piece, many of which were pleasingly thoughtful and interesting compared to the snarky feedback one often gets on Comment is Free. But what I hadn’t anticipated was the Twitter response, where there seemed to be a sense in some quarters that my remarks on gentrification betrayed a rather sinister agenda. Admittedly, some of this was just ideological cant (ironically of a Marxist persuasion, I suspect), but some of the critical feedback offered food for thought on how notions of self-organization and complexity applied to urban growth can be received – responses that I hadn’t anticipated or encountered before.

Some felt that to regard gentrification, or any other aspect of urban development, as something akin to a “natural” process is to offer a convenient smokescreen for the fact that many such processes are driven by profit, greed and venality – or as some would say, by capital. To consider these processes in naturalistic terms, they said, is to risk disguising their political and economic origins, and to belittle the sometimes dismaying social consequences. Indeed, it seems that for some people this whole approach smacks of a kind of social Darwinism of the same ilk as that which proclaims that inequalities are natural and inevitable and that it is therefore fruitless to deplore them.

I can understand this point of view to some degree, for certainly a “naturalism” based on a misappropriation of Darwinian ideas has been used in the past to excuse the rapaciousness of capitalist economies. But to imagine that this is what a modern “complexity” approach to social phenomena is all about seems to me to reflect a deep and possibly even dangerous confusion. The aim of such work is, in general, to understand how certain consequences emerge from the social and institutional structures we create. These consequences might sometimes be highly non-intuitive in ways that simple cause-and-effect narratives can’t hope to capture. They are intended to be partly descriptive – what are the key features that characterize such phenomena; how are they different in different instances? – and partly explanatory. Often the methods involve agent-based modelling, starting from the question: if the agents are allowed or constrained to interact in such and such a way, what are the results likely to be? In the current case, the question is: why do some areas undergo gentrification, but not others? I can’t begin to imagine why, regardless of how you feel about gentrification or what its socio-political causes might be, that question would not be of interest.

But to see such explorations as a kind of justification of what it is they seek to understand is to totally misconstrue the object. Look at it this way. There has been a great deal of work done on traffic flows, in particular to understand how they break down and become congested. It would be bizarre to suggest that such studies are seeking to excuse or justify congestion. On the contrary, their aim is generally to find the causative influences of congestion, so that traffic rules or networks might be better designed to avoid it. Similarly, attempts to understand economic crashes and recessions using ideas from complex-systems theory don’t for a moment take as their starting point the idea that, if we can show why such events emerge from our existing economic systems, we have somehow shown that these are things we must just lie down and accept. (Indeed, amongst other things they can counter the foolish delusion, popular pre-2008, that such fluctuations are a thing of the past.)

Now, you might say that I did however begin my Guardian piece with the suggestion that (according to the researchers who did the work it describes) gentrification is “almost a law of nature”. This is certainly what the paper implies – that this phenomenon is simply a part of the cyclic change and renewal that cities experience. Surely one would hope – I would hope – that this change happens in terms of relatively deprived neighbourhoods experiencing an improvement in facilities and amenities, rather than by the kind of wholesale demolition that was deemed necessary for the Heygate estate. But the bad aspects of gentrification include inadequate provision for existing residents and businesses affected by the soaring prices, loss of local character, uninhibited property grabs, and so on. It’s complicated, for sure.

(A word here: some folks in the Guardian comments have deplored the Heygate development, and my impression has been that some residents were compelled to move against their wishes. I rather fear that there is some truth too in the suggestions that the people who will benefit most will be property developers. But I spent a considerable amount of time in the mid-1990s in the adjacent Aylesbury estate, a similarly hideous brutalist high-rise development plagued with social problems. Any sense of community that existed there – and there certainly was some – survived in spite of the disastrous social planning that had created these “living” spaces, not because of it. Moreover, I think we should be extremely wary of romanticizing a development that owed its existence to very similar circumstances: it was built on the ruins of postwar slums where deprivation coexisted with a sense of community, and from which residents were similarly rehoused or displaced.)

In any event, it is essential that studies of complexity and self-organization in social systems are never used to justify the status quo. They need to be accompanied by moral and ethical decisions about the kind of society we want to have. The whole point of much of this work, especially in agent-based modelling, is to show us the potential consequences of the choices we make: if we set things up this way, the result is likely to be this. They might save us from striving for solutions that are simply not attainable, or not unless we make some changes to the underlying rules. This, of course, is nothing more that Hume’s admonition not to confuse an “is” with an “ought”. The theories and models by no means absolve us from the responsibility of deciding what kind of society we want; indeed, they might hopefully challenge prejudices and dogmas about that. I hesitate to suggest that this approach is “apolitical”, since science rarely is, and in social science in particular it is very hard to be sure that we do not pose a question in a way that embodies or endorses certain preconceptions. And I feel that sometimes this kind of research operates in too much of a political vacuum, as though the researchers are reluctant to acknowledge or explore the real social and political implications of their work.

So I am glad that the issue came up. Here’s the article.

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Grumble all you like that Brixton’s covered market, once called a “24-hour supermarket” by the local police, has been colonised by trendy boutique restaurants. The fact is that the gentrification of what was once an edgy part of London is almost a law of nature.

“Urban gentrification”, say Sergio Porta, professor of urban design at Strathclyde University in Glasgow, and his coworkers in London and Italy in a new paper, “is a natural force underpinning the evolution of cities.” Their research reveals that Brixton shares features in common with other once down-at-heel London districts that have recently seen the invasion of farmer’s markets and designer coffee shops, such as Battersea and Telegraph Hill. These characteristics, they say, make such neighbourhoods ripe for gentrification.

Whether it is the Northern Quarter in Manchester, Harlem in New York or pretty much everywhere in central Paris, gentrification is rife in the world’s major cities. You know the signs: one minute the local pub gets a facelift, the next minute everyone is reading the Guardian and sipping lattes, and you daren’t even look at the property prices.

The implications for demographics, crime, transport and economics make it vital for planners and local authorities to get a grasp of what drives gentrification. Urban theorists have debated that for decades. According to one view the artists kick it off, as they did in Notting Hill, moving into cheap housing and transforming the area from poor to bohemian – then investors and families follow. Another view says that the developers and public agencies come first, buying up cheap property and then selling it for a profit to the middle classes.

Porta and his colleagues have focused instead on the physical attributes that seem to make an area ripe for – or vulnerable to, depending on your view – gentrification. Do different neighbourhoods share the same features? The team looked at five parts of London that have gone upmarket in the past decade or so: Brixton, Battersea, Telegraph Hill, Barnsbury and Dalston.

All of them are some distance from the city centre. The housing is typically dense but modest: undistinguished terraced houses two or three storeys high, often of Victorian vintage. “This picture is pretty much that of a traditional neighborhood, far away from the modernist model of big buildings”, says Porta.

But the key issue, the researchers say, is how the local street network is arranged, and how it is plugged into the rest of the city. Each street can be assigned a value of the awkwardly named “betweenness centrality”: a measure of how likely you are to pass along or across it on the shortest path between any two points in the area. It’s a purely geometric quantity that can be calculated directly from a map.

All of the five districts in the study have major roads with high betweenness centrality along their borders, but not through their centres. These roads provide good connections to the rest of the city without disrupting the neighbourhood. Smaller “local main” streets penetrate inside the district, providing easy access but not noise or danger. “It’s this balance between calmness and urban buzz within easy reach that is one of the conditions for gentrification”, says Porta. These conclusions rely only on geography: on what anyone can go and measure for themselves, not on the particular history of a neighbourhood or the plans of councillors and developers. Looked at this way, the researchers are studying city evolution much as biologists study natural evolution – almost as if the city itself were a natural organism.

This idea that cities obey laws beyond the reach of planning goes back to social theorist Lewis Mumford in the 1930s, who described the growth of cities as “amoeboid”. It was developed in the 1950s by the influential urban theorist Jane Jacobs, who argued that the forced redevelopment of American inner cities was destroying their inherent vibrancy.

Jacobs’ views on the spontaneous self-organization of urban environments anticipated modern work on ecosystems and other natural “complex systems”. Many urban theorists now believe that city growth should be considered a kind of natural history, and be studied scientifically using the tools of complexity theory rather than being forced to conform to some planner’s idea of how growth should occur.

Gentrification is not just “natural” but healthy for cities, Porta says: it’s a reflection of their ability to adapt, a facet of their resilience. The alternative for areas that lack the prerequisites – for example, modernist tower blocks, which cannot acquire the magic values of housing density and frontage height – is the wrecker’s ball, like that recently taken to the notorious Heygate estate in south London.

The new findings could have predicted that fate. By the same token, they might indicate where gentrification will happen next. Porta is wary of forecasting that without proper research, but he says that Lower Tooting is one area with all the right features, and looks set to become the new Balham, just as Balham was the new Clapham.

[Postscript: I told Sergio that I would give full credit to his coworkers. They are Alessandro Venerandi of University College London, Mattia Zanella of the University of Ferrara, and Ombretta Romice of the University of Strathclyde.]