  Hjort and Poulsen (2019) frames the staggered arrival of submarine Internet
cables on the shores of Africa circa 2010 as a difference-in-differences
natural experiment. The paper finds positive impacts of broadband on
individual- and firm-level employment and nighttime light emissions. These
results largely are not robust to alternative geocoding of survey locations, to
correcting for a satellite changeover at end-2009, and to revisiting a
definition of the treated zone that has no clear technological basis, is
narrower than the spatial resolution of nearly all the data sources, and is
empirically suboptimal as a representation of the geography of broadband.
