The diffusion of social media coincided with a worsening of mental health conditions among adolescents and young adults in the United States, giving rise to speculation that social media might be detrimental to mental health. In this paper, we provide the first quasi-experimental estimates of...

This paper provides the first causal evidence that hostile activities online lead to physical violence. Given the recently documented relationship between pollution and social media, I exploit exogenous variation in local air quality as the first step to instrument for online aggression. In an...

This article analyzes under which conditions a manager can motivate a junior worker by verbal communication, and explains why communication is often tied up with organizational choices as job enlargement and collaboration. Our model has two important features. First, the manager has more...

The article studies the evolution of the U.S airline industry from 1995 to 2009 using T-100 traffic data and DB1B fare data from the U.S. Department of Transportation. Based on a differentiation in market size and major players, entry and exit, concentration, fares, service, costs and profits,...

This paper analyzes the birth of the Encryption Software Industry (ESI), a new market niche in the software industry. This work will report the main facts of entry and exit process, focusing on firm post-entry performance, on the different phases of competition during the industry evolution, and...

In this paper, we study the growth rates of 4-digit sectors in U.S. manufacturing. Two measures of size (value of shipments, value added) are considered, for each of the 38 years (1959-1996) of a sample of 458 4-digit sectors, drawn from the NBER Manufacturing Productivity database. Whole sample...

This paper provides estimates of price-marginal cost ratios or markups for 50 sectors in 8 euro area countries and the US over the period 1981-2004. The estimates are obtained applying the methodology developed by Roeger (1995) on the EU KLEMS March 2007 database. Five stylized facts are...

Between September 2021 and April 2022, anhydrous ammonia prices in the United States more than doubled, topping out at a record-high $1,300/ton. At the time, Senator John Boozman, Ranking Member of the Senate Committee on Agriculture, Nutrition, and Forestry, asked the Agricultural & Food Policy...