In existing literature, economic uncertainty may have positive, negative, or insignificant effect on crude oil prices. Based on our newly proposed two-stage tests and empirical analysis, we show that such disagreement is often caused by the conventional assumption on time-invariant market...

This article explores the impact of language proficiency on international trade by using panel data analysis. To do so, we construct a time-variant test-score-based measure of common language. Controlling for the standard gravity model variables, we find strong empirical evidence that English...