Empirical exercises in economics frequently involve estimation of highly nonlinear models. The criterion function may not be globally concave or convex and exhibit many local extrema. Choosing among these local extrema is non-trivial for a variety of reasons. In this paper, we analyze the...

This paper empirically investigates the possible market power effects of vertical integration proposed in the theoretical literature on vertical foreclosure. It uses a rich data set of cement and ready-mixed concrete plants that spans several decades to perform a detailed case study. There is...

Incompatibility in market with network effects reduces consumers' ability to "mix and match" components offered by different sellers, but can also spur changes in product attributes that might benefit consumers. In this paper, we estimate the effects of incompatibility on consumers in a classic...

This paper reviews recent methodological developments in the empirical analysis of imperfectly competitive markets highlighting outstanding problems. Some of these problems are econometric; e.g. the need for a deeper understanding of the small sample properties of our estimators. Most of the...

We test whether firms use incompatibility strategically, using data from ATM markets. High ATM fees degrade the value of competitors' deposit accounts, and can in principle serve as a mechanism for siphoning depositors away from competitors or for creating deposit account differentiation. Our...

This paper analyzes the concept of barriers to entry. It explains that the concept is a static one and explores the inadequacy of the concept in a world with sunk costs, adjustment costs and uncertainty. The static concept addresses the question of whether profits are excessive. The more...