(with Yoav Sivan)

Abstract. There have been few attempts to empirically explain the pursuit of short term relationships and sex in a formal context. Previous work has lamented the paucity of empirical studies which utilize incentive driven behavior to draw conclusions and recommend policy. We provide an empirical approach derived from a game theoretic model of social interaction and apply it to a population of high interest. Specifically, we apply the approach to a population of sexually active men who have sex with men (MSM) in a large metropolitan area and derive qualitative conclusions regarding how individuals behave in the marketplace for sex.

Abstract. Recent empirical work has investigated consumer purchasing decisions taking into account dynamic properties of the market, for instance rising product quality levels, e.g. (Melnikov, 2000). Taking such models seriously, we model evolving product quality levels over time and use the estimates to estimate purchase timing decisions of consumers. This results in demand estimates that tie levels and expectations of market conditions to current purchasing decisions through optimal purchase timing. We apply the estimation procedure to the new car market in four OECD countries over a thirty year period. Considering cars as durable goods which are financed at prevailing interest rates and whose value is affected by road infrastructure, we explain aggregate purchase decisions through dynamic changes in interest rates and infrastructure. In addition our estimates match stylized facts regarding the auto market, in particular qualitative data regarding car brands and cyclical patterns in demand.