My research focuses on social and economic systems with positive feedbacks.  In my current research I consider socially influenced purchasing behavior, competing technology standards, innovation diffusion and organizational problem solving.  I apply a broad range of methodological tools to these topics, including mathematical, statistical, computational and system dynamics modeling.

Below are links to two of my recent papers addressing positive feedbacks in business and economics:

ABSTRACT.  In this paper, I develop a model of consumer choice based on localized increasing returns.  Consumers choose products by first limiting their choice to a subset of options, in order to reduce the information costs of their decision or to satisfy product attribute requirements, and then selecting from this feasible set based on a combination of individual preferences and increasing returns to sales.  The market level consequences of the model are examined through simulation, and two key findings are explored.  First, the critical factor in determining the shape of the market share distribution is the distribution of feasible set sizes.  Second, in most cases, the resulting distribution of shares follows a power law.  This second finding is supported by recent empirical research and explains why in many markets a “Long Tail” of niche products is observed despite the winner take-all-prediction of previous increasing returns research.  I demonstrate that consumer preference data can be employed to predict market success with both global and local increasing returns, but that consumer choices more accurately reflect individual consumer preferences when increasing returns are localized.

ABSTRACT.  Some models suggest that markets with positive feedbacks or increasing returns have the potential to “lock-in” to inferior technologies while others predict that in the long run, the superior technology wins out.  In this paper, we find support for claims of both inefficient lock-in and long term efficiency by showing that efficient outcomes often only arise after an extended period in which inferior products dominate the market.  We also characterize the conditions that are most likely to sustain an inferior standard, and in particular, show that uncertain feedbacks reduce the likelihood of lock-in. Our findings support recent empirical evidence of unpredictable market outcomes in the presence of positive feedbacks.