We propose an approach to modeling and estimating discrete choice demand that allows for a large number of zero sale observations, rich unobserved heterogeneity, and endogenous prices. We do so by modeling small market sizes through Poisson arrivals. Each of these arriving consumers then solves...

A subset of harm reduction strategies encourages individuals to switch from a harmful addictive good to a less harmful addictive good; examples include e-cigarettes (substitutes for combustible cigarettes) and methadone and buprenorphine (substitutes for opioids). Such harm reduction methods have...