We study how political factors shape competition in the mobile telecommunication sector. We show that the way a government designs the rules of the game has an impact on concentration, competition, and prices. Pro-competition regulation reduces prices, but does not hurt quality of services or...

The combinatorial clock auction is becoming increasingly popular for large-scale spectrum awards and other uses, replacing more traditional ascending or clock auctions. We describe some surprising properties of the auction, including a wide range of ex post equilibria with demand expansion,...

This paper describes a field experiment in Oklahoma City Public Schools in which students were provided with free cellular phones and daily information about the link between human capital and future outcomes via text message. Students' reported beliefs about the relationship between education...

We evaluate the impact of a health information intervention implemented through mobile phones, using a clustered randomized control trial augmented by qualitative interviews. The intervention aimed to improve sexual health knowledge and shift individuals towards safer sexual behavior by...

Cellular technologies have become increasingly important in the developing world; infrastructure for mobile networks has expanded dramatically over the past two decades giving access to remote areas without previous phone service. Despite this expansion, relatively little is known about the...

The COVID-19 pandemic has devastated many low- and middle-income countries (LMICs), causing widespread food insecurity and a sharp decline in living standards. In response to this crisis, governments and humanitarian organizations worldwide have mobilized targeted social assistance programs....

We introduce a novel measure of segregation, experienced isolation, that captures individuals' exposure to diverse others in the places they visit over the course of their days. Using Global Positioning System (GPS) data collected from smartphones, we measure experienced isolation by race. We...

Traveling beyond the immediate surroundings of one's residence can lead to greater exposure to new ideas and information, jobs, and greater transmission of disease. In this paper, we document the geographic mobility of individuals in the U.S., and how this mobility varies across U.S. cities,...

We study the effect of information on technology adoption and productivity in agriculture. Our empirical strategy exploits the expansion of the mobile phone network in previously uncovered areas of rural India coupled with the availability of call centers for agricultural advice. We measure...

This short note constructs Mobility Zones to facilitate the discussion on the geographic extent of individual mobility restrictions to control the spread of Covid-19. Mobility Zones are disjoint sets of counties where a given level of individual mobility directly or indirectly connects all...