# **1. Introduction**

Job accessibility is potentially a key determinant of not only the productivity of labor forces in cities but also their welfare and poverty. Job accessibility is commonly referred to as the number or share of existing job opportunities a city resident can reach within a given amount of time. At the level of an urban area, a low level of job accessibility for city residents can inhibit the productivity gains from agglomeration economies by constraining a better matching between jobs and job seekers (Combes and Gobillon 2015; Duranton and Puga 2004). More importantly, limited job accessibility may disproportionally affect the economic performance of disadvantaged workers. In many African cities, lacking affordable and reliable transport, many people are too poor to use any transport and just walk to work (Lall, Henderson, and Venables 2017).<sup>2</sup> Low-income households that live farther away from clusters of jobs face higher commuting and job search costs. As the spatial mismatch hypothesis posits (see a review by Gobillon and Selod 2014), having such bad job accessibility could make them even poorer by limiting their employment outcomes.

However, which city residents face limited access to job opportunities depends on, among other factors, the shape of the city, the clustering patterns of employment, the function of housing markets, and transport networks. For example, low-income households may live in inner-city informal settlements by prioritizing their proximity to job opportunities over more desirable living conditions and incur environmental and health risks due to overcrowding and inadequate access to basic services. Living near clusters of jobs may be particularly important for the urban poor, who often engage in multiple temporary and casual jobs. However, the long-term influence of unfavorable living conditions on their well-being is a concern. Thus, it is imperative to empirically assess who suffers from limited job accessibility and whether choosing to live in informal settlements offers relatively good job accessibility to low-income populations in exchange for giving up decent living conditions. In a worse case, informal settlements provide neither good access to jobs nor a healthy environment, instead creating poverty traps (Marx, Stoker, and Suri 2013; Turok and Borel-Saladin 2018).

Unfortunately, empirical evidence on how job accessibility and poverty are linked in African cities is scarce. Such analysis requires the data on (a) the spatial distribution of jobs, (b) transport networks, and (c) housing rents and household consumption. Spatial distribution of jobs is hard to obtain for African cities, given the prevalence of informal jobs. Even more difficult is information about minibus networks, which is a common transport mode in many African cities. Although housing rents and household consumption are usually available in Living Standards Measurement Survey (LSMS) type household surveys, they are rarely representative at both the informal and formal residential areas. By addressing all these data challenges, this paper examines the link between job accessibility and urban poverty in an African city by assessing the spatial distributions of job accessibility, housing rents, and poverty.

Our approach is threefold. First, we assess the overall level of job accessibility for a city. Our study focuses on Nairobi, Kenya. A relatively monocentric city (Antos, Lall, and Lozano-Gracia 2016; Henderson et al. 2016), Nairobi accommodates more than 1 million residents in informal settlements, most of whom are tenants (KNBS 2012). The severity of living conditions in Nairobi’s informal settlements (particularly Kibera) has been widely documented (for example, Bird, Montebruno, and Regan 2017). We measure job accessibility based on the number of jobs accessible within a certain range of travel time from a residence or neighborhood. Second, we investigate who has better or worse job accessibility in Nairobi, by focusing on poorer people 2 In the Unites States, the poor live in central cities with better access to public transport (Glaeser, Khan, & Rappaport 2008).

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