Connected Substitutes and Invertibility of Demand
---- Acknowledgements -----
This paper combines and expands on selected material first explored in Gandhi (2008) and Berry and Haile (2009a). We thank Jean-Marc Robin for helpful discussions. We received useful comments from participants in the 2011 "Econometrics of Demand" conference at MIT. Adam Kapor provided capable research assistance. Financial support from the National Science Foundation is gratefully acknowledged. The views expressed herein are those of the authors and do not necessarily reflect the views of the National Bureau of Economic Research.