Kurmann and Otrok (2013) establish that the effects on economic activity from news on future productivity growth are similar to the effects from unexpected changes in the slope of the yield curve. This comment shows that these results become substantially weaker in the light of a recent update in the utilization-adjusted total factor productivity series produced by Fernald (2014).

What do patents tell us about the economic effects of future technological improvements? We identify aggregate and industry-level patent-based news shocks by exploiting changes in stock market valuations of firms that obtain patent grants. Our shocks resemble diffusion news: they do not affect total factor productivity in the short run but induce a strong permanent effect after five years. We find that patent-based news shocks produce positive co-movement between consumption, output, investment, and hours. They also generate positive responses in inflation and in the federal funds rate, consistent with standard New Keynesian models.

This paper provides a comprehensive survey of existing measures of uncertainty, risk, and volatility, noting their conceptual distinctions. It summarizes how they are constructed, their relative advantages in usage, and their effects on financial market and economic outcomes. The measures are divided into four categories based on the construction methodology: news-based, survey-based, econometric-based, and market-based measures. While heightened uncertainty is typically associated with negative real and financial outcomes, the magnitude of these effects and the interpretation of transmission channels crucially depend on identification considerations.