The paper introduces preference persistence into a dynamic discrete choice model of demand for durables. This persistence may arise, for example, when the products can be categorized into a few number of formats, which involve special knowledge, maintenance and upgrade. The standard optimal...

A multiproduct cost model is estimated on a panel of US local exchange carriers from the period 1989-1999. Unlike earlier econometric research on the industry, the model allows specification of cost inefficiency. This is needed to get consistent parameter estimates. Results show slight economies...