To date, the literature on quantile regression and least absolute deviation regression has assumed either explicitly or implicitly that the conditional quantile regression model is correctly specified. When the model is misspecified, confidence intervals and hypothesis tests based on the...

This study aims to demonstrate that the concentration (or distribution) of firm R&D intensities within an industry is closely related to the overall R&D intensity of the industry. Unlike the well-studied relationship between sales concentration, or market structure, and industry R&D intensity,...