publicaciones seleccionadas artículo Quality Differentiation with Flavors: Demand Estimation of Unobserved Attributes 2013 documento de trabajo Estimation of Unobserved Attributes Using a Control Function Approach, Modeling the Demand for Mint Flavored Gum 2013-04 Demand Estimation in the Presence of an Unobservable Product Attribute: The Case of Mint Quality 2012