marine cables (SMC) from Europe to Africa. The cables began arriving on the African coastline between 1997 and 2002, but only a few countries had access to them. We refer to these early cables as the "first-generation" SMCs to Africa. Also, the bandwidth capacity of these early submarine cables was still relatively low, limiting high-speed Internet access to a few locations. The construction of the undersea cables slowed between 2002 and 2008, partly due to the global financial crisis and dotcom bubble (D’Andrea and Limodio, 2019). However, between 2009 and 2012, Africa witnessed a boom in the arrival of ("second-generation") fiber-optic submarine cables, with the number of African countries with at least one submarine cable connection increasing from about 20 in 2008 to 52 in 2012 (see Figure 1).<sup>19</sup> Figure 2 shows the gradual arrival of the submarine cables between 2000 and 2018. Further, the landing points of the submarine cables were mostly cities along the coast.

However, to get this Internet available to end-users, it has to travel through the "middlemile" and "last-mile" networks.<sup>20</sup> The "middle mile" consist of the national (fiber) "backbone" infrastructure which transmits high-capacity internet from the landing points of the submarine cables throughout the domestic network. Along these fiber backbone networks, there are several connection points, referred to as "Internet nodes", that connect the backbone to the "last-mile" infrastructure–which is essentially the form of infrastructure that households and firms connect directly to for Internet. In Africa, the last mile network usually consists of fiber broadband cables, and mobile internet (via mobile phone towers) (Hjort and Poulsen, 2019). The national backbone infrastructure also played an important role in connecting (neighboring) landlocked countries to the submarine cables.

As highlighted by Hjort and Poulsen (2019), in almost all African countries, the backbone network were built by national telecom companies, albeit, in some instances, private telcos extended the network. Also, many of these backbone networks were built many years before to the arrival of the submarine cables, as Internet was hitherto transmitted via telephone cables.

We treat the arrival of the SMCs as a positive shock in Internet connectivity. This is because, Internet via these cables is: (i) faster, and (ii) cheaper than satellite-based Internet. In Togo and Mauritania, for instance, connections to the submarine cables reduced the cost of international bandwidth for 1 Mb/s from $1,174 to $73 and $3,500 to $29 respectively.<sup>21</sup> This obviously

> 19As of the end of 2018, only three African countries (Central African Republic, Eritrea, and South Sudan) were unconnected to at least one submarine cable. Also, every seaboard country in Africa, except Guinea-Bissau and Eritrea, has at least one submarine cable landing. See https://www.broadbandcommission.org/Documents/ working-groups/DigitalMoonshotforAfrica_Report.pdf

> 20 The "middle-mile" can be likened to the network of electricity transmission lines that carries high voltage energy from generation plants to substations. The "last-mile" on the other hand can be likened to the network of distribution lines which carries low voltage electricity from substations to customers.

> 21See the World Bank’s World Development Report 2021. https://openknowledge.worldbank.org/bitstream/ handle/10986/35218/9781464816000.pdf

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