Empirical work supports the theory that decentralization and suburbanization of jobs benefit non‐central locations near the transport infrastructure. Evidence supports that suburbanization was encouraged by a well‐developed railroad system and/or the freeway network in the US, Spain and Japan.<sup>29</sup> Evidence on developing countries also suggests a somewhat similar pattern. In the case of China, data confirm that each railroad ray displaced 25% of core city industrial GDP and 16% of 1990 core city total GDP to suburbs. For China, however, radial highways do not seem to play an important role in explaining de‐concentration of production from the CBD. Highways, on the other hand, seem to matter for India where the movement of formal sector manufacturing from urban regions to rural parts of a district is explained by the Golden Quadrilateral highway. A similar case is observed in Indonesia where the process of decentralization of industrial production from the urban CBD has been facilitated by the building of a highway linking the city to nearby hinterlands.<sup>30</sup> Although there are no studies on the impact of improvements in transport infrastructure on the spatial organization of economic activity within African cities, limited available evidence available on cross‐city work in Africa suggests that there could be considerable potential for an expansion of transit networks. For instance, in Zambia, only 5% of all trips are longer than 10 km, while for the U.S. 5% of trips are longer than 50km, implying that people in African cities are unable to take advantage of a full range of job opportunities.<sup>31</sup> Further, cross‐city evidence in Africa indicates that periphery cities with better road connection to port cities grew faster vis‐à‐vis cities with poor road connection, suggesting that an efficient transport network in Africa is likely to enhance city productivity in the same way as in most cities around the world.<sup>32</sup> Similar to improvements in physical infrastructure, advances in communication and computing technologies have facilitated the fragmentation of tasks and activities of firms across various sites. Such separation of tasks is expected to occur when the cost of disintegration and the possible loss of agglomeration benefits is more than offset by lower production costs at a cheaper location. Innovations in electronic infrastructure largely explain the migration of back‐office jobs to suburbs of a city or to smaller cities while the management or headquarter activity that is a personal or face to face communication intensive task is being retained in the CBD.<sup>33</sup>

> 29 For the impact of roads and highways within cities, see, Baum‐Snow (2007), Duranton & Turner (2011) for US; Hsu and Zhang (2014) for Japan; Garcia‐López et al. (2013) and Garcia‐López  (2010b) for Spain.

> 30 See Baum‐Snow et al. (2012), Roberts et al. (2012) and Deng et al. (2008) for China; Ghani et al. (2012, 2014) for India; Henderson and Kuncoro (1996) for Indonesia. Highways in China tend to explain the decentralization in population, Baum‐Snow et al. find that with each increment of radial road capacity causing a 3 to 5.5 percent decline in central city population from 1990 to 2010. This finding corroborates with Baum‐Snow (2007) results for the US, though the magnitudes are much larger, given the higher income and incidence of auto commuting in the country. In addition, Baum‐Snow (2014) finds that the new radial roads on US inter‐state highways had a much larger effect on residential decentralization vis‐à‐vis employment decentralization. For more on the effects of railroads in China, see Banerjee et al. (2012), Baum‐Snow et al. (2012) and for India, see, Donaldson (2014). 31 Schafer (2000).

> 32 See Storeygard (2012)

> 33 Duranton and Puga (2005), Ota and Fujita (1993), RossiHansberg et al. (2009), Anas et al. (1998)

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