Applied researchers most often estimate the demand for differentiated products assuming that at most one item can be purchased. Yet simultaneous multiple purchases are pervasive. Ignoring the interdependence among multiple purchases can lead to erroneous counterfactuals, in particular, because...

We introduce a Generalized Nested Logit model of demand for bundles that can be estimated sequentially and virtually eliminates any challenge of dimensionality related to large choice sets. We use it to investigate quantity discounts for carbonated soft drinks by simulating a counterfactual with...