The Excel file at the link above contains the Environmental Policy index for the United States as well as two sub-topic indices for Renewable Energy Policy and International Climate Negotiations. The data series are available monthly over the period from January 1981 to March 2019.

These indices, built using machine learning techniques, represent the share of articles about environmental policy in ten large newspapers, and are normalized such that their average value over the 1981-2019 period is equal to 100. The newspapers included in our index are the New York Times, Washington Post, Wall Street Journal, Houston Chronicle, Dallas Morning News, San Francisco Chronicle, Boston Herald, Tampa Bay Times, San Jose Mercury News and San Diego Union Tribune.