FQREG: Stata module to estimate quantile regression for non-negative data with a mass-point at zero and an upper bound

fqreg estimates quantile regression for non-negative data with a mass-point at zero and an upper bound, using the specification and method described in Machado, Santos Silva, and Wei (2016, "Quantiles, Corners, and the Extensive Margin of Trade," European Economic Review, forthcoming).