  Internet access is essential for economic development and helping to deliver
the Sustainable Development Goals, especially as even basic broadband can
revolutionize available economic opportunities. Yet, more than one billion
people still live without internet access. Governments must make strategic
choices to connect these citizens, but currently have few independent,
transparent and scientifically reproducible assessments to rely on. This paper
develops open-source software to test broadband universal service strategies
which meet the 10 Mbps target being considered by the UN Broadband Commission.
The private and government costs of different infrastructure decisions are
quantified in six East and West African countries (C\^ote D`Ivoire, Mali,
Senegal, Kenya, Tanzania and Uganda). The results provide strong evidence that
`leapfrogging` straight to 4G in unconnected areas is the least-cost option for
providing broadband universal service, with savings between 13-51% over 3G. The
results also demonstrate how the extraction of spectrum and tax revenues in
unviable markets provide no net benefit, as for every $1 taken in revenue, a $1
infrastructure subsidy is required from government to achieve broadband
universal service. Importantly, the use of a Shared Rural Network in unviable
locations provides impressive cost savings (up to 78%), while retaining the
benefits of dynamic infrastructure competition in viable urban and suburban
areas. This paper provides evidence to design national and international
policies aimed at broadband universal service.
