This article addresses unit root testing on regulated series through the variance ratio (VR) statistic of Nielsen (2009). The asymptotic distribution of the regulated VR statistic is developed with and without OLS detrending. Results of Cavaliere and Xu (2011) are extended by also developing the...

An important issue in estimating cartel overcharges is to have a reliable estimate of the but-for-the-cartel price. While the cartel price is observable, the but-for-the-cartel price is not. A construction of the but-for-cartel-price evolution by assuming perfect competition, i.e. that price...