**1. Introduction**

"The state must also *lead* the process of industrial development, by developing strategies for technological advance in priority areas. This type of State action ... seeks to *create* and *shape* markets and systems." [1] (p. 47)

The celebrated growth of the African continent's countries over the past four decades has been accompanied and underpinned by the growth of Africa's cities [2], which are growing at the highest rates in the world [3,4]. Notwithstanding the dramatic projections of the continent's urban dwellers tripling from 548 million in 2018 to 1.5 billion in 2050—around 22% of the global urban citizenry at that time [4]—African cities remain characterized by high levels of informality, poverty, inequality, unemployment and infrastructure and service provision deficits. Rapid urbanization is unfolding in the absence of any significant industrialization [3]. The question of what urban development and industrialization trajectories may ensue on the continent and how sustainably the growing needs of the African urban citizenry will be met, is hence important for (note that this study builds on recent work—i.e., [5,6]—that set the foundation for the emphasis on social innovation articulated in this paper) (1) meeting global sustainable development goals [7,8] and (2) mitigating against the exacerbation and/or increased growth of existing socio-economic ills, such as poverty and inequality, which characterizes the urban divide in Africa [9].

**Citation:** Peter, C. Social Innovation for Sustainable Urban Developmental Transitions in Sub-Saharan Africa: Leveraging Economic Ecosystems and the Entrepreneurial State. *Sustainability* **2021**, *13*, 7360. https:// doi.org/10.3390/su13137360

Academic Editor: Harald A. Mieg

Received: 23 May 2021 Accepted: 25 June 2021 Published: 30 June 2021

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**Copyright:** © 2021 by the author. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https:// creativecommons.org/licenses/by/ 4.0/).

African cities have become targets for multi-national corporations seeking to secure urban real estate in the "new scramble for Africa", i.e., for knowledge cities, global cities, eco-cities and smart cities [10]. Yet, in contrast to this push for grand master planning styled urban development and the establishment of wholly new green fields satellite cities [10–12], the scholarly discourse on African cities has, for the greater part of the past two decades, focused on the need to pay detailed attention to the strategies and tactics through which the "everyday" navigation of dual formal and informal systems is navigated [13–17]. More recently, in response to this emphasis on the quotidian, several scholarly contributions have argued for a re-appraisal of the role of the state, namely, that the state, through both its presence and absence, significantly shapes the development of African cities [18,19]. This tension—between bottom-up and top-down intervention priorities—in the southern urbanism literature closely mirrors similar tensions in the debates on social innovation [20].

This top-down, bottom-up tension speaks directly to what scales of intervention are required, what the target of intervention should be (i.e., who, what) and what mode (i.e., how) of intervention is required for SUD in Africa. It also raises the question of what roles —i.e., the state, private sector, civil society and academia—can play. In this respect, considering the role that social innovation can play—with the support of the aforementioned sectors and, particularly, the state [21]—in engendering sustainable urban development (SUD) in Africa is worth exploring in tandem. This is particularly the case as social innovation (taking a cue from Moulaert et. al. [22] this study adopts a broad, all-encompassing definition of social innovation of as "conscious corporations to non-profit charitable ventures" [23] (p.2)) is widely recognized as "'transformative' in relation to systemic change" as well as "'instrumental'" in responding to the need for the provision of social services [24], both of which are clearly required when contemplating transitions to SUD in African cities. Moreover, social innovation can emerge independently from the aforementioned sectors alone, from collaboration and cooperation between them [21,24] and from top-down, bottom-up and hybrid approaches that integrate both [20].

In response to this, this study explores the African urban condition to help diagnose what kind of sustainability transition is required in the African context and what role social innovation can play in catalyzing transition. It draws on a range of scholarly and policy outputs to characterize the African urban condition and its specificities, peculiarities and vulnerabilities. This enables an argument to be made for social innovation that is informed by the following three considerations: (1) the appropriate scale of intervention that is required (i.e., small to intermediate scale cities), (2) the target of intervention (i.e., the food– water–energy–transport nexus that middle class African households are heavily dependent on) and (3) the appropriate mode of intervention for African cities (i.e., in situ development in slums and informal settlements, leveraging low-tech sustainability-oriented and green offerings in combination with fourth industrial revolution offerings).

This study adopts an economic ecosystem lens because it places a specific focus on local economic development [25]. It argues that—by adopting an economic ecosystem perspective and focusing social innovation agendas on the scales, targets and mode of intervention identified in this study—transitions to SUD can be seeded, catalyzed and consolidated at local and local–regional scales, empowering local authorities and social innovation-based organizations to deliver on SUD agendas. In this framing, small to intermediate scale African cities serve as incubators of niche social innovations and catalysts for local transitions to SUD, respectively. These cities are ideal candidates for sustainability transitions that are infrastructure and technology intensive, as well as inclusive, precisely due to their more manageable developmental scales. Moreover, due to their location along corridors that typically connect larger cities to rural towns and areas, they can act as a "glue" in the rural–urban assemblage, helping overcome rural–urban divides on the continent to some extent.

With respect to broader, macro-scale transitions to sustainability, this study theorizes that by deploying the multi-level perspective on sustainability transitions (MLP) [26], small-scale, decentralized development at local and local–regional scales—driven by social

innovation—can help develop the niche innovations and economic ecosystems [25,27] that can drive broader scale transitions. In this casting, economic ecosystems established in small to intermediate sized cities—which draw on both green/sustainable solutions and fourth industrial revolution offerings to innovate context-specific offerings (i.e., products and services)—act as distributed "engines" of social innovation and local economic diversification that cumulatively drives national and regional-scale economic diversification trajectories.

This framing, in turn, helps elucidate the role of the entrepreneurial state in actualizing SUD in Africa. Namely, the role of the entrepreneurial state is to shape SUD transitions in Africa through directing, building and supporting local economic ecosystems that foster social innovation for SUD at the appropriate scales, for the targets identified and in the modes stipulated in this study. This includes managing the complexity of hybrid topdown bottom-up participation, protecting the interests of the marginal majority poor and maintaining a focus on scaling for sustainability at broader scales.

In addition to its emphasis on local economic development, this study also adopts an economic ecosystem lens because it is agnostic towards formal–informal sector dualism, i.e., both these considerations are important for actualizing local transitions to SUD in the African context. The economic ecosystem framing helps overcome formal–informal sector dualism, providing a framework for a post-dualistic conception of formal and informal sectors, one that enables a holistic, heterodox perspective that is more suited to the realities of the African urban context.

In the next section the dimensions of African urbanism are accounted for and serve as a basis upon which the scales, targets and modes of intervention are rationalized. Section 3 offers a specific definition of what a sustainable African city would ideally be characterized by and identifies the stabilization of the middle class as key to the broader transition, as well as the means through which that can be achieved, i.e., by targeting "nexus" (i.e., food–water–energy–transport) costs. Section 4 positions local economic ecosystems as vehicles through which infrastructural, technological and economic diversification can be achieved (i.e., in both formal and informal sectors, as well as local, national and regional), drawing on the multi-level perspective as a framework for transitions to sustainability. Section 5 discusses the key theoretical contributions of this study and Section 6 summarizes and concludes the study. Section 7 identifies its key limitations and suggests avenues for future (theoretical and empirical) research on this basis.

It is important to note that the vast heterogeneity of the African continent limits the validity of any developmental approach that attempts to be comprehensive. Hence, this study maintains a strict focus on the urban condition, drawing on well-established common developmental conditions and challenges in African cities, while acknowledging that accommodating territorial differences and sensitivity to context and heterogeneity is a critical and necessary consideration in formulating and implementing this approach. Moreover, while the study draws on Africa-wide data and findings for pragmatic reasons relating to data availability, the approach that is developed in this study is mainly directed at Sub-Saharan African cities.

#### **2. African Urbanism: The Scale, Target and Mode of Intervention**

The African continent's celebrated growth [2]—characterized by even growth across sectors that fueled consistent GDP growth over the past four decades—is largely underpinned by its urbanization rates [3], which are projected to soon be the highest in the world [28]. The continent exhibits the highest city growth rates in the world [4]. City growth rates hovered at around 4% for the four decades spanning from 1950 to 1990 and is projected to be at least 3% by 2035–2040 [4]. Consequently, the continent's highest performing 18 cities are likely to achieve a purchasing power of USD 1.3 trillion by 2030 [3,29]. Africa's middle class is expected to grow to 1.1 billion in 2060, up from 355 million in 2010 [3,30] and its labor force is expected to reach 1.1 billion, exceeding that of China and India [2] by 2034 [28]. Hence, Africa's cities have become targets for the global multinational corporations seeking to secure and re-valorize urban real estate in the new scramble for Africa [12].

However, African cities are characterized by dual formal–informal systems spanning almost every sector and activity (i.e., trade, service provision, employment, housing, land ownership and leasing and finance). The informal sector in Africa employs 66% of Africa's non-agricultural labor force, while contributing around upwards of 35% (35% in middle income countries, 40% and higher in low-income countries) of GDP [31]. Urban slum dwellers increased from 31 % in 1995 to 62% in 2012 [32] and it can reasonably be expected that this growth has continued with rapid city growth rates. The large infrastructure and service deficits that prevail across the continent and its cities, alongside the prevalence of dual formal and informal systems, present perhaps the largest obstacle to stabilizing the African middle class and alleviating those in poverty. The prevalence of slums and informal settlements—which are characterized by piecemeal planning and uneven development typically serves as a barrier to the provision of bulk infrastructures, such as water and sanitation, bulk energy supply, waste management and roads and transportation [3]. Demand is met through a combination of formal and informal service providers, often at higher cost to the poor, who cannot physically access formal bulk infrastructures and service provisions [3]. Moreover, Africa and its cities are heavily dependent on imports, such as goods, food and fuel, to meet local demand, rendering them vulnerable to exogenous change effects [33].

Three key additional—and peculiar—factors are critical to account for in respect of aspirations to SUD on the continent.

*Scale of intervention.* First, contrary to popular perceptions of urbanization on the continent, the large majority of growth has not been occurring in the large metropoles of the continent (e.g., such as Lagos and Kinshasa), but has rather been occurring in small to intermediate cities instead (i.e., 63.9%) [34]. With 54% of growth occurring in small cities (i.e., 100,000–500,000) and 9.9% in intermediate cities (i.e., 500,000–1,000,000) [34] and the majority of these cities springing up along corridors that connect larger cities, the spatial transition that African urbanization is undergoing offers up a key opportunity to leapfrog urban development by focusing efforts at smaller, more manageable scales yet still driving macro-scale transitions at the same time. This indicates that inclusive, participatory-based approaches are more achievable as well, as the scale of engagement is smaller. It also speaks to the need for stronger decentralization for local and local–regional economic diversification; decentralized infrastructures and service provisions are key to this transition. Hence, the scale of intervention can be identified as that consisting of small to intermediate cities, focusing on local and local–regional (the term "local–regional" is used in this article to differentiate between transnational regions and local regions) developmental scales.

*Target of intervention.* Second, the African middle class does not resemble the global middle class and is in contrast—in reality—a middle-class precariat. Whereas the global middle class is defined as people living on USD 10–100 per day, the African middle class is defined as those living on USD 2–20 per day [35]. The African middle class in 2010 constituted 34% of the total African population and around 60% of this 34% actually survived on incomes of USD 2–4 per day (i.e., the "floating middle class") [35]. Hence, the African middle class is considerably vulnerable to exogenous shocks and changes, with household budgets under severe and persistent strain, especially due to heavy dependence on imports of goods, food and energy (i.e., nexus effects; see Section 3.2). Only 4% of Africans earn above USD 10 per day and constitute only 2% of the global middle class, with 50% of Africans living under the poverty line of USD 1.25 per day [36]. Hence, the target of intervention is clear: transitioning the precarious middle class into stability and growing it, particularly by focusing on household budgets, alongside stabilizing formal and informal sector SMEs that typically provide services at the—aforementioned—scales of intervention.

*Mode of intervention.* Third, in contrast to the first wave of urbanization that saw urbanization accompany the industrialization (i.e., the industrial revolution from 1750 to 1950) of now developed nations, urbanization in Africa has largely been unfolding in the absence of any significant industrialization [3,15,29]. Extractive and agrarian activities largely underpin growth on the continent. Notwithstanding, significant tertiary sector growth has unfolded on the continent over the past decade, with telecommunications, finance and banking services reaching more people due to the—mainly ICT—platforms that technological advancements of the third industrial revolution have enabled [36–39]. This speaks to the need for and potential for Africa to leapfrog the type of industrialization trajectory that the cities of the developed world underwent. This is critical in respect of the need for low-carbon, sustainable growth that is just, inclusive, resource efficient and is hence suited to the pressing concerns of the 21st Century [29,30], particularly the need to meet global Sustainable Development Goals (SDGs). This in turn is a strong indication of the mode of intervention that is most appropriate for African cities, that is, in situ development that leverages the convergence of sustainability oriented and/or green solutions, as well as fourth industrial revolution offerings that are appropriate for and fit the African urban context and its needs (see Section 3.1).

In summary, this study enables us to discern (1) the scale of intervention, (2) the target of intervention and (3) the mode of intervention that ascribe a "fit-for-purpose" approach towards engendering sustainable urbanism in African cities. This in turn helps frame the role social innovation can play in generating radical, top-down, bottom-up and hybrid solutions [20] to the pressing—wicked—SUD challenges facing African cities. Moreover, it provides focus for sectoral intervention and support, particularly the role that the (entrepreneurial) state can play in supporting social innovation for local development in African cities, with a view to stimulating local economic development and broader transitions to sustainability at the same time.
