This paper presents global evidence on the impact of expansion in mobile telephony and broadband Internet services on economic development at the subnational level. Leveraging two decades of satellite data on nightlights and the global expansion of 2G, 3G, and 4G mobile networks in over 34,000 subnational districts in 120 countries, it documents three main findings on the effects of mobile phones on local economic development (proxied by nightlights): I. The expansion of mobile coverage has a positive effect on economic activity. Using the GDP-nightlights elasticity from Henderson et al. (2012), the estimates suggest a GDP growth-mobile phone penetration elasticity of 0.018-0.023
II. While mobile broadband (3G & 4G) Internet connectivity is associated with economic development across all countries, 2G connectivity boosts local economic growth mainly in developing countries
III. The economic effects of expansion in mobile network connectivity are more pronounced in countries that hitherto had limited access to fixed-line telephone infrastructure, thus highlighting the importance of mobile phones to developing countries in leapfrogging the technology ladder.