“…It is then virtually impossible to observe the transaction prices for all products within each location. A similar problem is likely to arise if there are many products available, as, again, in the automobile market (see, e.g., Langer, 2016;Allcott and Wozny, 2014;Murry, 2017, for papers relying on such data in this market). If we do not observe all the transaction prices (p d j ) d=1,...,n D corresponding to product j, but at least one price p d j j for each j, then we can use p j = p d j j and apply our methodology since Assumption 2 holds.…”