The Excel file at the link above contains the Environmental Policy Uncertainty (EnvPU) index for the United States. The data series is available monthly over the period from January 1990 to March 2019.

This index, built using machine learning techniques, represent the share of articles about environmental policy (see our EnvP index) that cover environmental policy uncertainty. The EnvPU index is normalized such that their average value over the 1990-2019 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.