In this paper I analyze GMM estimation when the sample is not a random draw from the population of interest. I exploit auxiliary information, in the form of moments from the population of interest, in order to compute weights that are proportional to the inverse probability of selection. The...

This paper examines the construction of a price index based on an estimated demand system. In principle the method examined can produce a price index that accounts for introduction of new products and quality changes in existing products. However, I isolate two key assumptions that have to be...

The study of differentiated-products markets is a central part of empirical industrial organization. Questions regarding market power, mergers, innovation, and valuation of new brands are addressed using cutting-edge econometric methods and relying on economic theory. Unfortunately, difficulty...

The ready-to-eat cereal industry is characterized by high concentration margins, large advertising to sales ratios, and numerous introductions of new products. Previous researchers have concluded that the ready-to-eat cereal industry is a classic example of an industry with nearly collusive...

Models of consumer behavior play a key role in modern empirical Industrial Organization. In this paper, I survey some of the models used in this literature. In particular, I discuss two commonly used demand systems: multi-stage budgeting approaches and discrete choice models. I motivate their...

This paper explores the relationship between shelf prices and manufacturers' coupons for 25 ready-to-eat breakfast cereals. Contrary to the predictions of static monopoly price discrimination, we find the shelf prices for a particular brand in a particular city are generally lower during periods...

We study the trade-offs faced by Internet Service Providers (ISPs) that serve as platforms through which consumers access both television and internet services. As online streaming video improves, these providers may respond by attempting to steer consumers away from streaming video toward their...

This is an invited chapter for the forthcoming Volume 4 of the Handbook of Industrial Organization. We present empirical models of demand and supply in differentiated products industries with an emphasis on the key ideas arising from the recent applied literature. We start with a discussion of...

We report results from a validation study of Nielsen Homescan data. We use data from a large grocery chain to match thousands of individual transactions that were recorded by both the retailer (at the store) and the Nielsen Homescan panelist (at home). First, we report how often shopping trips...

Dealing with endogenous regressors is a central challenge of applied research. The standard solution is to use instrumental variables that are assumed to be uncorrelated with unobservables. We instead assume (i) the correlation between the instrument and the error term has the same sign as the...