  Roughly 3 billion citizens remain offline, equating to approximately 40
percent of the global population. Therefore, providing Internet connectivity is
an essential part of the Sustainable Development Goals (SDGs) (Goal 9). In this
paper a high-resolution global model is developed to evaluate the necessary
investment requirements to achieve affordable universal broadband. The results
indicate that approximately $418 billion needs to be mobilized to connect all
unconnected citizens globally (targeting 40-50 GB/Month per user with 95
percent reliability). The bulk of additional investment is for emerging market
economies (73 percent) and low-income developing countries (24 percent). To our
knowledge, the paper contributes the first high-resolution global assessment
which quantifies universal broadband investment at the sub-national level to
achieve SDG Goal 9.
