# 2. **Data**

Senegal represents a valuable case study. The rise in the number of cellphone users and Internet subscribers in the country over the past decade has been significant compared with peer countries. Figure 1 illustrates the mobile cellular subscriptions and fixed broadband subscriptions in Senegal relative to peers—Côte d’Ivoire, Kenya, and Rwanda—as well as among the 5th and 95th percentiles overall in Sub-Saharan Africa.

The data on consumption and poverty are derived from official household budget surveys: the 2011 ESPS-II and the 2017–18 ELEPS. The 2011 ESPS was a nationally representative survey that was fielded between August and November 2011. It was conducted effectively with 17,891 of the 18,180 households sampled given that the response rate was 98.4 percent. About a third of these households were interviewed using the entire household questionnaire on expenditure. The 2017–18 ELEPS is comparable with the 2011 survey. The ESPS was administered among 1,065 of the 1,200 households sampled given that the response rate was 89 percent. The sample was spread across the country according to three geographic areas: Dakar, other urban centers, and rural areas.

To measure access to fixed broadband Internet services across Senegal, the analysis relied on information on the locations of fiber-optic transmission nodes that was obtained from the Africa Bandwidth Maps database.<sup>5</sup> The analysis considers how distance to operational fiber-optic nodes may influence welfare and poverty across the country. Map 1, panel a, shows the locations of fiber-optic transmission nodes in Senegal. These nodes correspond to add or drop points (entrance or exit) in the long-haul fiber networks. It is useful to think of long-haul fiber networks as motorways that have junctions (on and off ramps that is, add and drop points) that feed smaller class roads (access fiber, wireline, and wireless networks). In the motorway scenario, even if a household is located close to the motorway, it may be a long drive to the nearest junction. The same applies to fiber-optic networks, in which the speed of fixed broadband Internet is determined by proximity to the transmission nodes rather than the network lines connecting the nodes. The transmission nodes are categorized by operational status: operational, under construction, and planned or proposed.

Mobile coverage data are drawn from two sources: the Mobile Coverage Maps database and mobile operators in the country. Data on mobile phone coverage and mobile broadband Internet coverage compiled in the Mobile Coverage Maps database by Collins Bartholomew are based on voluntary submissions made directly by mobile operators for the purposes of constructing roaming coverage maps for end users. The temporal coverage of the data varies depending on 2G and 3G coverage, respectively, in 2011–17 and 2014–17.<sup>6</sup> To ensure that the findings are not an artifact of potential missing information in the Mobile Coverage Maps database, the analysis also utilizes 2G and 3G coverage information collected directly from the three major mobile operators in Senegal: Expresso, Orange (or its local subsidiary Sonatel), and Tigo. While the coverage maps obtained from Expresso and Tigo are limited to 2016, Orange’s coverage maps are available for 2016–18. Orange-Sonatel dominates the fixed and mobile markets, dwarfing

> 5 See Africa Bandwidth Maps (database), Hamilton Research, Bath, UK, http://www.africabandwidthmaps.com/.

> 6 The Mobile Coverage Maps database contains no information on 4G coverage. Moreover, the coverage maps depend on information shared voluntarily by mobile operators. So, their quality should be checked for completeness against other sources of data. For this, the analysis here relies on data collected directly from major mobile operators.

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