Where is the matter of urban Africa?

Since the turn of this century, immaterial, informal and ephemeral dynamics have fascinated many scholars of African urbanism, one consequence of which has been a recurrent inattention to the tangible, haptic city in favour of the powers of representation, ingenuity, language and speculation. AbdouMaliq Simone, one of the foremost theorists of African urbanism, emphasized that it is the practices of social collaboration and the potentialities of speculation and improvisation that make urban Africa ‘work’, rather than any substantial materiality (Simone Reference Simone2004a; Reference Simone2004b). A spectral, shadow world of the occult, rumour and hidden symbolic meaning has been foregrounded, in which metaphor and interpretation are regarded as the active agents, rather than material substance (Blunt Reference Blunt2019; De Boeck and Plissart Reference De Boeck and Plissart2004). In an urban context such as Kinshasa, a place of extreme material breakdown where many systems and infrastructures have collapsed, Filip De Boeck (Reference De Boeck2011: 279) has argued that it is in language that urban life gets made: ‘words offer one of the most powerful tools, one of the most important building blocks with which to conquer, alter and erect the city over and over again’. One particularly prevalent theme has been the transitory qualities of urban life, and in particular the role of informality. Since Keith Hart’s (Reference Hart1973) original analysis of the ‘informal economy’ as economic activity taking place beyond the purview of official systems and oversight, informality has become a powerful analytic in examining how urban Africans have responded to urgent and chronic uncertainties on the continent. Leveraged to engage with a diverse range of urban challenges, informality has helped shape recent work on emergent urban dispositions such as ‘hustle culture’, forms of marginality and innovative resourcefulness (e.g. Thieme Reference Thieme2017; Hecht and Simone Reference Hecht and Simone1994; Lindell Reference Lindell2010).

Taken as a whole, this wave of African urbanist scholarship – though varied in its empirical context and approach – can be seen as linked by its commitment to the voices and experiences of the urban majority; foregrounding experiences that might previously have been regarded as ‘peripheral’ or ‘marginal’ to more structural analyses of African cities. This recentring of African agency – and thus also of the complexity of interpretation, language, symbolic worlds and meaning-making – was long overdue. It can be seen as a response to a previous academic generation’s focus on crisis and the breakdown of urban systems, planning and politics – themes that dominated both academic and public debate about Africa at the end of the last century (see Nuttall and Mbembe Reference Nuttall and Mbembe2008: 1–35). That work tended to see the informalization of African cities in terms of failure: economic, structural and political. From the 1980s onwards, the trope of ‘Africa in crisis’ was widespread, and it still casts a long shadow (see Roitman Reference Roitman, Goldstone and Obarrio2017). In an era of infrastructural breakdown that marked many African cities in the 1980s and 1990s, the continent’s burgeoning metropolises were widely regarded as failed places, unable to meet even the basic needs of their citizens. This narrative was part of a wider discourse of Africa as a continent of failed states, in which crisis – in various forms – was understood to be both pervasive and persistent (see Roitman Reference Roitman, Goldstone and Obarrio2017; Bayart Reference Bayart1993). Widespread in policy and scholarly circles was a notion that Africa had started to go backwards: the modernizing promise of the independence moment had not only stalled but begun to disintegrate. This was sometimes experienced, as James Ferguson (Reference Ferguson1999: 13) put it, as ‘modernisation through the looking glass’, where an anticipated ‘developed’ future seemed to be receding into the distance. Economic and political decomposition was indexed by infrastructural decay, in which roads, buildings, housing projects, water systems – all considered to be distinctive signs of ‘modernity’ – fell into disrepair (see Mbembe and Roitman Reference Mbembe and Roitman1995). This ‘dilapidation’ of progress and modernity was thus not just metaphorical; it was materially felt in everyday life. Consequently, by the 1990s, high levels of informality, infrastructural breakdown and poor governance had engendered frequent depictions of African cities as places of failure, places where not only had the tenets of development failed to adhere but where life in urban ‘slums’ was a world of abjection and dehumanization (Ferguson Reference Ferguson1999; Davis Reference Davis2006).

Against this backdrop, the desire to highlight the possibilities of informality and the rich sociality and vibrancy that characterize urban African life was an important corrective. This agenda was central to Simone’s (Reference Simone2004b) influential concept of ‘people as infrastructure’: as African cities could not depend on material infrastructures, the cracks were filled by people’s improvisational strategies, interdependencies and socialities. Attempts to think with African cities in more lateral, imaginative ways thus moved away from teleological trajectories of progress and development (or their absence) and towards a more provisional, open-ended engagement that worked with notions of transformation, opportunity and agency, rather than abjection and failure (Guyer Reference Guyer2011). Over time, this crystallized into a deeper sense that to understand African cities required attention to forms of urbanism that defied colonial or ‘Western’ logics and classifications. This was at the heart of Mbembe and Nuttall’s (Reference Mbembe and Nuttall2004) provocation: what would it mean to write the world from an African metropolis? In this approach, while recognizing entrenched inequalities and exclusions, African urbanism was understood to be alter – subject to different logics of development, placemaking and ordering compared with cities elsewhere in the world. As De Boeck (Reference De Boeck2011: 269) put it in reference to the dense, complex neighbourhoods of contemporary Kinshasa, the city does not look ‘into the mirror of colonialist modernity to design itself’.

Collectively, such approaches have provided a complex portrait of the ways in which urban Africans have adapted to structuring economic and political changes over the decades, finding room to manoeuvre and to endure in the face of chronic crisis (Simone and Pieterse Reference Simone and Pieterse2017). But even as this was to be welcomed as an overdue recentring of everyday human agency, in the last few years a critique has begun to emerge that the emphasis on ingenuity and agency has swung too far, to the detriment of analysing conditions of extreme economic insecurity. Often grounded in political economy, these voices are calling for renewed attention to questions of urban inequality, precarity and exclusion in the context of neoliberalism, austerity and the ways in which colonial spatial strategies – such as apparatuses of urban segregation, securitization and police violence – persist in new guises (Rizzo Reference Rizzo2017; Wiegratz etal. Reference Wiegratz, Martiniello and Greco2018; Jones etal. Reference Jones, Kimari and Ramakrishnan2017). Such work demonstrates an ethical commitment to thinking through the effects of neoliberal politics and capitalist restructuring, focusing on what government commitments to ‘development’ or ‘deregulation’ look like from ground level, and on how urban communities must negotiate the endurances of colonial injustices. This is what Wale Adebanwi (Reference Adebanwi2017) has called ‘the political economy of everyday life’: the capacity to live amid zones of dispossession, indebtedness and exclusion. Such work constitutes a powerful call to recognize the recursive patterns of exclusion that shape life in urban Africa, yet it also indicates a swing back towards earlier scholarly themes that focused on structural conditions, economic failure and crisis – albeit with a greater attentiveness to the voices and experiences of urban Africans at the bottom of the pyramid.

Our interest here is not to weigh in on this structure–agency balancing act, but rather to ask what such questions might look like when seen from elsewhere. Despite their differing agendas, what these waves of scholarship tend to have in common is that the material world remains in the background. Even as each wave has sought to push back against a previous trajectory, implicitly preserved is the notion that the material, tangible world is passive: shaped by, rather than an active participant in, a linguistic, experiential – human – world.

If the ‘crisis’ literature saw the breakdown of material infrastructures as a symptom, indicating pervasive political and economic malaise, then the ‘agency’ wave tended to see urban sociality as vibrant despite the challenges of the physical city: material forms were peripheral or incidental to the ‘real’ city that was happening in the domains of discourse, ingenuity and language. In both cases, the materials and stuff of the city were regarded as inert, or simply in the background. The most recent scholarship has started to examine physical landscapes – such as transport systems, land or infrastructures of food or communications – but even where objects, buildings or spaces do appear, they tend to be subject to very human forms of interpretation: dilapidated infrastructure is seen as a space for political activism, for example, or everyday objects are regarded as containers for the retelling of human stories. In essence, to repeat an early mantra of the ‘material turn’ in the social sciences and humanities, objects are analysed in terms of what they mean, rather than what they do (see Brown Reference Brown2001). While strategy, collaboration, tenacity and rumour are powerful forces shaping African cities, and although infrastructures are indeed often inadequate or broken, housing provision is derisory, or services are inoperative, it does not follow that the material form of the city is passive, ineffective, or simply a slate on which human stories are carved. In fact – and this may even lie dormant or unacknowledged at the heart of some writings that foreground the discursive and symbolicFootnote ¹ – the haptic, tactile city, in all its fragmentation, is itself generative of powerful social and political dynamics, influencing the trajectories of urban lives in all their messy complexity (see Smith Reference Smith2019).

It should be noted here that the beginnings of a literature on the materiality of urban life in Africa is slowly emerging, and we will address this in more detail shortly. But first we wish to emphasize our conviction that studying the stuff of African cities is not a move away from, or a diminishment of, the important and powerful scholarly preoccupations that we have outlined above. Rather, it is a way to get inside these debates from new angles, and to see how such dynamics are often grounded in the very substances of the city. It is this that lies behind our commitment to urban materialities – not just to put materiality back in the picture, but to attend to the mutual imbrication of human and non-human worlds. In this special issue, we begin to explore how the flows, accumulations and transformations of human and non-human materials, diverse technologies and the regulatory regimes designed to shape and contain them are crucial to thinking about African cities – that is, how politics, socialities and subjectivities ‘find traction in their entanglement with materialities of milieu’ (Fontein Reference Fontein2015: 9) and are therefore central to the ongoing constitution of urban worlds. This is a fundamental recognition – shared by all the authors brought together here – of the un-foreclosed and often uneasy imbrications of the material and the imaginative, matter and meaning, the semiotic and the sensory, in the making and remaking of urban lives, geographies and politics. To explore this further, we now turn to the larger literature of the ‘material turn’ and how it may help complicate and deepen approaches to understanding urban Africa. We then highlight the work of others involved in this emerging conversation, before outlining our own contributions in this special issue.

Stuff that matters

We start from a commitment to examining the transformative potential of the material: how stuff is always an active participant in the making of cities – though its material form and relational situation may be provisional – and what a focus on such participation might reveal about the capacities, limits, possibilities and resistances of urban worlds. The stuff of cities is often subject to formal planning and regulation, but such attempts at ordering, we observe, usually emerge in piecemeal and incomplete ways. This is a reminder that cityscapes are never blank spaces on which human imperatives can be smoothly imposed, and that emergent human–thing relationalities are often marked by disjunctures, fractures, uncertainty and incoherence, with all the potentialities and opportunities, as well as contestations and exclusions, that these can involve.

An example may be helpful here: during the production of this special issue, our attention was also on the final stages of the construction of an elevated expressway that now extends 27 kilometres through downtown Nairobi. Its completion seemingly timed to coincide with the final stages of Uhuru Kenyatta’s presidency, and funded and constructed through a public–private partnership with China (see Nyabiage Reference Nyabiage2022), the expressway was about a lot more than facilitating the flow of traffic through the city. A wide range of actors, in shifting configurations, were responsible for bringing the expressway into being: engineers, authorities, project managers and publics, certainly, but also cement, steel, sand, machinery, water, labour, money, plans, advertising and many more. The expressway has its origins in Vision 2030, a blueprint for development launched by the Kenyan government back in 2007 to power Kenya onto the global stage and turn Nairobi into a ‘world-class’ city (Smith Reference Smith2017). But the time-space between initiation and completion has generated a complex material–social–political nexus, in which the blueprint has been fractured by uncertainties and controversies, from the prioritization of elite mobility at the expense of ordinary Nairobians to the destruction of urban ecologies and the collapse of a bridge that was under construction (Lunzalu Reference Lunzalu2020). It is not just vehicles that are mobilized by the expressway: vast quantities of materials – including 280,000 tonnes of cement, 350,000 tonnes of sand and 90,000 tonnes of steel, according to Kenya National Highways Authority – have been deployed, the procurement of which has in turn set in motion new business opportunities and networks of profit and influence (Musyoka Reference Musyoka2021).

The material substances involved are far from passive: in analysing the creation of the expressway, we could take any of these elements and examine how they helped to actively propel the process. We are wary, though, of focusing on singular objects in isolation; things that ‘move and engage but do not otherwise transform themselves’ (Harvey and Knox Reference Harvey, Knox and Harvey2014: 8). In thinking about urban materialities, we try to go a bit further, to explore how human and material worlds are always entangled in mutual processes of making and becoming. Here, we draw on the work of Tim Ingold, and his emphasis on the improvisatory, forward-flowing momentum in which the properties of materials, forms of knowledge and the skills, habits and ideas of humans are interconnected and mutually constituted (Ingold Reference Ingold2013). His approach emphasizes the way in which things, people and environments grow and change together – sometimes uneasily – and that what something is, or what its possibilities are, is not preconceived or known in advance but worked out in the flow of its becoming. From this perspective, things are inherently unstable: boundaries become fuzzy, and things are mutable and multiple.

To return to the example of the expressway, just a few conversations (undertaken as part of a different research project) revealed that what appears to be a physically massive structure, a solid imposition of concrete looming over the city, is much more ambiguous. It materializes different things to different people: a project manager proudly itemized its feats of engineering and the skilled manipulations of vast quantities of concrete. A taxi driver could only describe its significance in terms of a cost–benefit analysis of what it costs to drive on it versus how much time he would save by not sitting in traffic. For an office worker in one of the high-rise offices that sit alongside it, the elevated expressway meant a dark shadow permanently hanging over her working day, as it blocked the light through the windows. For a student at Nairobi University, the physical form of the expressway did not correlate with its hidden agenda. What it looked like and what it did were two different things: ‘[T]his expressway is just politics. It’s all just the legacy vanity of [President] Uhuru Kenyatta, he wants a big thing that people see and think of him. It’s not about actually making life better for Nairobians. Why didn’t he just build a statue?’Footnote ² In terms of traffic congestion, its impact is far from clear: expats and wealthier Nairobians delight at the speed with which they can now reach the airport, but early uptake has been low due to high tolls. Roadworks have continued on the old highway, which runs underneath the expressway, making city traffic even slower for some time. The expressway was built and financed by the state-owned China Road and Bridge Corporation as part of China’s strategic Belt and Road Initiative in Africa. This investment is to be recouped via toll charges over a planned twenty-seven-year period, after which management will be transferred to the Kenyan government. This public–private financial entanglement is of a scale currently without precedent in Africa (Nyabiage Reference Nyabiage2022).

In various ways, then, Kenyans will be paying for the road for a long time to come. What seems like a fait accompli is revealed to be unfinished and multiple, with effects that are not easily contained or gauged through evaluative frameworks that seek to measure impact or success. Its effects on the city are ongoing; even though construction may be finished, the project will require maintenance and repair if its form is to hold together. The concrete will degrade; systems of payment and traffic flow will need to be updated. The politics of its construction will continue to play out, as will the geopolitics of its financing, which is part of a wider escalation of Chinese involvement in Africa (Han and Webber Reference Han and Webber2020). But more than that, the expressway will always remain incomplete in the sense that, as an intervention in the wider landscape of Nairobi, it will continue to mediate the way in which life unfolds, facilitating, constraining and colouring the city’s relational flows. The expressway is both a coming together of particular histories and an unfinished projection into the future.

So far, we have emphasized that materials, objects and stuff act in the world, often in complex relations with other kinds of actors, including humans. But questions remain about how we account for their participation in what seem to be human creations, such as cities. Sometimes, critiques of the material turn in anthropology and related disciplines have suggested that its approaches draw an equivalence between human and non-human action, as though concrete or steel were regarded as sentient beings, and distinctions between different kinds of ‘allies’ are flattened out in the attempt to ‘dethrone’ the human subject (Clough Reference Clough2008). Yet, as multiple scholars have explicated at length, it is perfectly possible to recognize the active role of the material world and the entanglement of humans in powerfully affective networks with non-humans, while also acknowledging that there is nevertheless something distinctive about human agency and sociality (Long and Moore Reference Long and Moore2013: 18). As Harvey and Knox (Reference Harvey, Knox and Harvey2014: 6) point out, the vitality of things ‘requires no intention or human-like quality, it simply refers to the way in which specific material configurations are actively engaged in shaping relations and in that sense are social actors’. In focusing on the stuff of cities, we are therefore not denying the significance of social, political or economic processes so much as seeking to understand their complex, mutual imbrications with multiple, emergent things and materials.

In some ways, the approach that we are advocating reverses Mary Douglas’s (Reference Douglas2003 [1966]) classic argument in Purity and Danger while also building on it. In thinking through how certain substances are constituted as waste and dirt, Douglas argued that this is an essentially social process: that the value and meaning of stuff is wholly socially constituted and has nothing to do with any inherent properties of stuff itself – that is, that dirt is a cultural category rather than pre-existent. Conversely, we – along with many other scholars of material culture – seek to explore how the possibilities for social constitution and contestation derive from potentialities inherent in materials: that materials are active participants in this process. Nevertheless, this approach also recognizes that individual and/or collective human thought, action and contestation are also largely shaped by a drive to create or impose order, establish stability and contain meaning and value. In our view, however, the actualizations of such a distinctly human imperative (Long and Moore Reference Long and Moore2013) are always influenced by – and ultimately often defied by – the profoundly uncertain potentialities of stuff to always be or become something else.

What is therefore important here is that focusing on things is not just about extending sociality to non-human or material others, but that their inclusion in the analysis fundamentally re-shapes the conversation. In the 1980s, feminist anthropology pushed home the point that simply ‘adding women and stirring’ was insufficient for the profound realignment of the discipline that feminist critique demanded – and that it risked ‘black-boxing’ gender studies into a niche sub-concern while leaving the larger discipline unreformed (Moore Reference Moore1988: 9). We are cognisant that ‘adding stuff and stirring’ is similarly inadequate. The attention to the material world is not simply about rebalancing the scales of older Cartesian dichotomies by bringing the unheeded stuff of African cities back into focus. Like both feminist and postcolonial critiques, the materiality turn promises and demands much more. As we have suggested, some studies ostensibly of objects and material flows often fall into patterns of interpretation, rather than following the action. Stuff is taken to be only a metaphor for human politics, meaning-making and contestation, rather than as the substantive grounds from which potentialities for human/non-human relationalities and meaning-making emerge. By falling back on older Cartesian distinctions between mind and body, culture and nature, meaning and matter – where potency and consequence ultimately lie only with the former – such ‘materiality-lite’ approaches do not fulfil the transformative potential that the materiality turn demands. To do so may involve a re-thinking of spatially and temporally linear notions of cause and effect, and a challenge to outdated but still prominent ideas about ‘agency’. That is, we need to approach ‘agency’ not as an inherent, predetermined quality of people (or, for that matter, of animals, materials or objects), nor as some kind of synonym for ethical action and political freedom (Laidlaw Reference Laidlaw2002). Rather, it may help to approach it as an emergent effect of human and non-human relations and socialities in time – or even to use it as a verb. Tim Ingold has proposed ‘agencing’ as preferable to agency, to better evoke the way in which ‘agency is not given in advance of action, as cause to effect, but is rather ever forming and transforming from within the action itself’ (Ingold Reference Ingold2017: 17). This helps to get at agency as a quality that is produced, unfinished and active, rather than preordained. It encompasses the physical, material, performative, social and semantic aspects of world-making in place and time, including politics and social relations as well as representation and meaning.

In the brief sections that follow, we explore four problematics that we find particularly fruitful for thinking through our approach to materiality, participation and the making of urban worlds.

Emerging materialities of urban Africa

There are now some indications that the ways of thinking, approaching and encountering stuff that we have outlined above are starting to reconfigure the study of urban Africa. Such work is emerging all the time, and our overview here in no way attempts to be comprehensive. Rather, it points to research that further illuminates and enriches our efforts in this special issue. Our interest in how stuff becomes an active participant in generating the contingent grounds of possibility for urban life resonates with recent work that attends to the material conditions of the urban, as well as its aspirational qualities. Julie Archambault’s (Reference Archambault2018) work on cement and concrete in urban Mozambique is instructive here. Among her interlocutors, bags of cement and concrete blocks have acquired a new currency, articulating new kinds of aspirations and desires. Concrete, she argues, is not simply a reflection of social transformation, nor only an index of progress or social status; rather, it is itself generative, ‘participating in shaping and inspiring these very transformations’ (ibid.: 703). Conversely, Gabrielle Hecht’s (Reference Hecht2012; Reference Hecht2021) extensive work on mining and other forms of toxic extraction in Africa emphasizes not the aspirational but the destructive affordances of stuff. She demonstrates that the permeation of toxic residues in urban areas of Johannesburg, Soweto and parts of urban West Africa have enacted a slow violence of environmental contamination and racial capitalism that delimit the possibilities of urban life (Hecht Reference Hecht2021).

Elsewhere, infrastructural assemblages and the technopolitics of material systems and networks have proved fertile ground for thinking through the ways in which materiality animates urban possibility. In Nairobi alone, new research has emphasized how infrastructures such as piped water (Schramm and Ibrahim Reference Schramm and Ibrahim2021; Kimari Reference Kimari2021) and mobile communications systems (Guma Reference Guma2020) are not stable forms controlled by planning or policy, but are contingent assemblages that gather together particular histories of intervention and repurposing. The kinds of connection (or disconnection) that are fostered by water pipes, pumps or mobile communications animate new socio-technical configurations, restricting or widening the horizons of the possible. Such material–spatial–technical relations can also help constitute online sociality, with implications for how we think through forms of political action. Adopting a ‘politics of things’ approach to analysing election campaigning in urban Zambia, Wendy Willems (Reference Willems2019) explores how the physical recirculation of digital content and the mediatization of urban spaces are crucial to tracing how political discourse is generated and political publics are constituted both online and offline.

Where earlier literatures may have focused on failures of urban administration as symbolic of political collapse, newer work has turned to the derelict materialities of urban management to examine how this generates alternative kinds of city-making. Constance Smith (Reference Smith2018; Reference Smith2019) traces how the dereliction of public housing in Nairobi accumulates, generating a material excess in which remains and residues – colonial and postcolonial – foster new kinds of history-making and political action. Urban political ecology influences Jacob Doherty’s (Reference Doherty2019) approach to the animal, human, microbial and infrastructural interrelations of Kampala’s waste crisis, and how these kindle what he calls ‘filthy flourishing’ in the city. Attention to both the failures of waste management and the substantive potentiality of waste itself shows how waste shapes urban conditions and the forms of thriving that occur amid the accumulation of urban trash. Meanwhile, Filip De Boeck’s influential work on Kinshasa has shifted gear to examine the ways in which metaphor and discourse are formed in relation to the material conditions of life. Together with photographer Sammy Baloji, he has developed a topographical mode of urban theorizing that centres on the constitutive possibility of the ‘hole’ (see also Dawson; Smith, this issue). The power of the hole is such that it shapes not only the conditions of life, but also forms of linguistic, economic and political practice. From potholes to graves to mining, the hole has ‘become a local master trope, a conceptual figure, to express the dismal quality of urban life in the postcolonial city’ (De Boeck and Baloji Reference De Boeck and Baloji2017: 150). Ultimately, the hole underpins what De Boeck calls ‘the dark matter of the urban praxis’ (ibid.: 150), influencing how life is lived in, through and despite urban disintegration.

Shape of the issue: sections and articles

The articles assembled here are organized into three sections. The first, entitled ‘Sand, concrete and construction materials’ presents articles by Armelle Choplin and Katherine Dawson that examine concrete and sand – a vital component of concrete – respectively. Given the recent dramatic expansion of large-scale construction in many African cities, this is an appropriate place to begin to consider the consequential potentialities of stuff in relation to the rapid pace of urban growth. Both articles are grounded in ethnography generated in West African contexts, and both approach the circulation of building materials with an eye on broader questions of political economy, livelihoods, inequality and the environment, but also on the intersection of meaning and metaphor that emerges from them. In the context of the Lagos–Abidjan corridor, Choplin explores the possibilities inherent in rapidly expanding demands for, and the production of, cement for the creation of new mega-wealthy and politically powerful African entrepreneurs. Dawson closely examines the intersections of labour and sand in and around Accra’s construction boom, showing how marginalized urban residents also stake claims to a share of the potential wealth of construction materials. As well as highlighting the diverse possibilities inherent in flows of cement and sand, both articles also reveal the remarkable capacity of – and the struggles faced by – protagonists in West Africa to actualize the opportunities that emerge from these expanded flows of construction materials. They therefore serve as a useful reminder that being attentive to the subjunctive possibilities inherent in materials does not mean denigrating human skill or capacity, but rather highlights the ways in which such skills can be animated by, or flow from, the stuff of urban landscapes.

If the mobilization of construction materials in Africa’s expanding cities has the potentiality to make possible new kinds of urban livelihoods, socialities and politics, then so do the productive contingencies of food. The next section, ‘Senses, animals and corporealities’, opens with Joost Fontein’s examination of East Africa’s largest goat market, and the processes that transform animals into meat products for human consumption. He traces the constitution of bodies, subjectivities and livelihoods as well as the flows of sometimes hazardous waste in Nairobi’s Kiamaiko goat industry. Here, flows of human and animal bodies, corporeal materials and products, and waste from goat lorries and slaughterhouses link urban and regional landscapes in very material ways. Like sand extraction in Accra, these flows create the conditions of possibility for new livelihoods, new bodies and new subjectivities, as well as new forms of wealth creation and social and political action and organization. But they also challenge existing power structures, and hence call forth forms of regulation. In such contexts, it can be hard to pinpoint processes of cause and effect. This exemplifies a larger theme of the issue: that proper investigation of the properties of materials and the contingent possibilities they offer necessarily raises questions about conventional linear assumptions about time, causation and about what constitutes ‘agency’. Humans and animals, food and waste all create the conditions of possibility for the city yet to come in ways that show how the politics of meaning is entangled with the potentialities of stuff.

The relationalities between classification, sensory experience and the excessive qualities of urban stuff are exemplified by Nick Rahier’s article and its ‘gustatory explorations’ of ‘city futures’ in Kenya’s secondary city of Nakuru. Rahier focuses on the material properties of food and the power of taste for triggering forms of urban imagining and future-making, linking bodies to cities through the entanglement of taste and temporal flows. His ethnography centres on the notion of kienyeji, a decidedly Kenyan term that is hard to translate but is often glossed to mean foods that are more ‘authentic’ or ‘clean’ and that are often linked to a nostalgia for a perceived untainted, rural past. In Kenya, the properties of kienyeji food are often contrasted with the hazards of ‘fake’ foodstuffs, which are widely understood to be dominant in urban markets. Such ‘fake’ foods range from highly processed ‘unhealthy’ products to scares over contamination and counterfeit goods (see also Smith, this issue). In celebrating and tasting kienyeji foods, Nakurians are making explicit moral claims about time: pasts and futures are remade through corporeal and sensorial processes of ingestion and consumption. In this way, in contrast to the emphasis in the proceeding articles on material spatialities, Rahier’s discussion makes explicit what possibilities are generated by material links across temporal expanses.

The moral and physical hazards of ‘fake’ foods link back to concerns about dangerous leakages (material and political) in Fontein’s article and bring these into conversation with Constance Smith’s article in the final section, ‘Planning and regulating uncertainty’. Foregrounding a devasting series of building collapses in Nairobi, she explores the literally shifting terrain of the city’s ongoing construction boom, examining how verticality and materiality are linked by a concern with what is going on underneath the surface. Seeking to unravel the imbrication of urban materialities and metaphors, she traces how the ‘underneath’ of construction is both material – a subterranean undermining of high-rise buildings – and metaphorical, in that Nairobi’s collapsing buildings are often diagnosed as ‘fake’, in so far as their surface appearance cannot be taken at face value. Fake buildings are understood to be generated by what she terms ‘grey development’: an assemblage of opaque business dealings, substandard construction materials, inadequate foundations and disregard for regulations and planning. Here, the properties of materials, and the (im)moral economies of construction, afford wealth for some but at the cost of others’ lives, livelihoods and futures. The relationality of the material to the metaphorical, and the capacity of substance and stuff to generate political economic conditions, speak directly to the larger promises, yet to be realized, of the materiality turn discussed above.

Continuing the theme of planning and regulation, Morten Nielsen examines the circulations of ‘bedroom drawer blueprints’ and the ‘acutely potent’ forms of vernacular urban modelling they constitute in Maputo, Mozambique. In the absence of centrally planned urban development, residents of Maputo adopt their own forms of planning through the exchange of blueprints for houses that they plan to build eventually. Nielsen shows how the properties of documents intersect with notions of expertise and the production and dissemination of knowledge that shapes ideas about how the city should – or could – be built. Indeed, the future possibilities that are conjured up, or threatened, by the properties of the materials they involve, also have other material forms beyond the belated imposition, contestation or nefarious failure of official regulation. Nielsen argues that it is the capacity of these ‘bedroom drawer blueprints’ to ‘move between different material forms and modalities that gives them their particular aesthetic potency and drive’. This seems a fitting place to conclude, exemplifying as it does the larger point of our whole special issue: that it is in the complexity, multiplicity and diversity of urban materialities from which the contingent grounds of possibility for urban life, politics, socialities and livelihoods – for the city yet to come – emerge.