As a preface to this special issue, this paper has two parts. The first part summarizes the scale and importance of the sustained and rapid growth of the informal economy and employment in the urban economic system in worldwide; analyzes the differences between countries and regions and their reflection on urban space, especially in China; and then discusses the limitations and problems of traditional urban planning in dealing with the development of urban informal economy from both theoretical and practical perspectives. The second part introduces the six articles included in this issue. Three of them are from foreign scholars and about the latest international research findings on urban informality. They explore in depth the development and governance of informal cities in developed countries represented by the United States, the informal housing improvement in developing countries and the mistakes and limitations of urban planning in dealing with the informal economy and space. The other three papers are from Chinese scholars and discuss respectively the job- living spatial mismatch for informal workers, the informal housing and community building and the informal use and governance of urban public space, presenting the problems and challenges in the domain of urban spatial planning in face of the pervasive informal economy

This article draws from the introduction and conclusion chapters of our edited book, The Informal American City: Beyond Taco Trucks and Day Labor (Mukhija and Loukaitou-Sideris 2014), which examines the “informal revolution” in American urban life. Through a series of case studies, we empirically and theoretically explore a growing phenomenon more often associated with developing countries than with industrialized ones. While informal urbanism is usually dismissed by planners and policymakers as marginal or even criminal, our case studies from across the country, including Los Angles, Sacramento, Seattle, Portland, Phoenix, Kansas City, Atlantic City, and New York City, challenge such narrow conceptions.

Surprisingly, even the scholarly planning and urban design literature rarely addresses informal urbanism despite its increasing presence. Therefore, we wish to depart from the conventional wisdom and examine the unexpected presence,  proliferation, and vibrancy of informal activities in different U.S. settings and cities. But rather than romantically celebrating informality, we are keen to develop more sophisticated ways to recognize, understand, and address it. We also argue for an explicitly spatial understanding of informality and its settings; and discuss how planners, policy makers, urban designers, and communities can respond to the new emerging landscape of opportunities and challenges.

Informal activities in U.S. cities are widespread and varied. Most of them are not criminal in nature, nor are they limited to instances of economic survival. And while informality has often been associated with immigrants, informal activities are pervasive and spread across different social groups, diverse urban settings, and different geographical regions of the country. Formal and informal activities may at times conflict and at times overlap or depend on one another. Case studies of such activities help reveal the logic and underlying rationality of informality, and the structural linkages between informal activities and the larger political economy of cities and regulations. They also show the contradictory nature of informality, with both potential winners and losers associated with informal activities.

Some myths and misconceptions about informality have developed over the years. One such myth is that urban informality is part and parcel of the Global South, and only appears in very poor and marginalized neighborhoods of cities of the Global North. However, urban informality of different types is now quite visible even in middle-class and affluent neighborhoods of the Global North. A second myth assumes that formal and informal activities and settings are always distinct and rigidly separated. However, we do not find such drastic separation between some formal and informal settings in cities. A third myth is that informality is a temporary phenomenon and an ephemeral construct; however, the ubiquity and persistence of many informal activities and settings tells us otherwise. Lastly, notions that informality is always a virtue, or the opposite—
it is always negative, belie the fact that informal activities are not homogenous but rather depend on context and circumstance. Rather than perpetuating these myths, planners and policy makers should deepen their understanding of informal urbanism and take into consideration their specific social and physical context, before responding to the challenges and opportunities of informal urbanism.

This study draws critical issues on urban informal real estate markets through lessons learned by academics and practitioners based on empirical evidence from Brazil, India, and China. The first part provides a brief synopsis of how policy makers viewed informal settlements at the time of the World Bank’s study. The second part is a brief analysis of three key policy interventions designed to improve the functioning of informal real estate markets, i.e., in-situ upgrading, offering private property rights, and slum redevelopment. The third part concludes by proposing three research questions that need to be addressed to better intervene in informal real estate markets.

The informal economy is a significant component of urban economy in global south. Comparing with the field of economic policies, there are few studies focusing on how to support informal economy through policies nowadays in the field of urban planning. In the context of planning as the central tool to regulate and marginalize informal economy, reconsidering informal economy from the aspect of spatial planning is important. The paper firstly describes the scale, the categories and the contribution to the urban economy’s growth of informal economy through data. Second, series differential theories and policies towards informal economy are reviewed. In the third part, some cases in global south indicate that some cities provide the proper livelihood for the informal economy through transforming the urban policies and planning strategies, including infrastructures in public spaces, home-based work and waste picker organization. Finally, the paper holds the view that the planners need to improve the planning method facing informal economy. The challenge that the gap between theory and practices of informal economy is increasing in case of regulation is still the main planning method. 

From the perspective of urban informality, this paper reviews the development of slums in Rio de Janeiro and the evolution of related policies, then analyzes the experience of slums upgrading in this region. In general, the policy in Rio which has transformed from ignorance, to forced eviction and removal, and then to upgrading and renewal, is moving towards an equitable and human one. Although due to the economic recession and political corruption, the current policy is facing the problem of inefficiency, the case of Rio illustrates the process of the urban government seeking for an appropriate position of urban informality in the spatial and institutional dimensions, which provides implications for the renewal of “urban villages” in Chinese cities.

In recent years, job-housing spatial mismatch becomes more and more common for metropolitan areas globally, and related issue on job accessibility receives increasing attention from policy makers and policy researchers. As an important link between residential and employment functions, transportation infrastructure is believed to be an important means to increase job accessibility based on existing urban pattern. This paper summarizes the establishment and changes of job-housing spatial relation, as well as the impact of transportation infrastructure on the job accessibility. Accumulated studies show that the public transportation infrastructure directly impact on employment opportunities and the living cost, especially for the low-income and middle-income groups. Increasing investment on the public transportation infrastructure inputs will improve employment ratio significantly. Compared with the original job-housing mismatch model in North America, job-housing spatial relationship in China are more complicated due to rapid suburbanization, new town development and new industrial zone development. Lack of public transportation in suburban area leads the vulnerable groups to a more disadvantaged situation. Therefore, under various cultural backgrounds and development stages, impact of transportation infrastructure on the improvement of job accessibility might be different. Appropriate traffic infrastructure investment will improve job accessibility, balance and optimize job-housing spatial relationship, and also increase employment opportunities for the low-income group, thus has profound influence for urban development in the future.

In the current stage of globalization, city competition could be regarded as the competition of talents, as globalization has been powered by knowledge and talent flows. Meanwhile, sociospatial polarization has been even more obvious in global cities. Most global cities are confronted with similar housing crisis: the flood of immigrants has led to the sharp increase of housing demand, along with housing price and rent; on the other hand, housing becomes unaffordable for more people in the context of income polarization. Thus, affordable housing policies have resurged in many global cities in order to boost city competition and maintain social stability, which can be referenced by Shanghai. In the lens of the global city theory, the paper reviews the affordable housing policies in London, New York and Singapore in recent decades. The comparative study of policy contents and outcomes leads to the discussion on the policy convergence and contextual distinctiveness. In the end, this paper analyses the problems and institutional contexts of the affordable housing policies in Shanghai to makes targeted suggestion for further housing policy.