Ali Hortacsu

The Winner's Curse, Reserve Prices and Endogenous Entry: Empirical Insights From eBay Auctions.

Internet auctions have recently gained widespread popularity and are one of the most successful forms of electronic commerce. We examine a unique dataset of eBay coin auctions to explore the determinants of bidder and seller behavior. We first document a number of empirical regularities. We then specify and estimate a structural econometric model of bidding on eBay. Using our parameter estimates from this model, we measure the extent of the winners curse and simulate seller revenue under different reserve prices. Copyright 2003 by the RAND Corporation.

Product Differentiation, Search Costs, and Competition in the Mutual Fund Industry: A Case Study of S&P 500 Index Funds

We investigate the role that nonportfolio fund differentiation and information/search frictions play in creating two salient features of the mutual fund industry: the large number of funds and the sizable dispersion in fund fees. In a case study, we find that despite the financial homogeneity of S&P 500 index funds, this sector exhibits the fund proliferation and fee dispersion observed in the broader industry. We show how extra-portfolio mechanisms explain these features. These mechanisms also suggest an explanation for the puzzling late-1990s shift in sector assets to more expensive (and often newly entered) funds: an influx of high-information-cost novice investors.

Mechanism Choice and Strategic Bidding in Divisible Good Auctions: An Empirical Analysis of the Turkish Treasury Auction Market

We propose an estimation method to bound bidders’ marginal valuations in discriminatory auctions using individual bid-level data and apply the method to data from the Turkish Treasury auction market. Using estimated bounds on marginal values, we compute an upper bound on the inefficiency of realized allocations as well as bounds on how much additional revenue could have been realized in a counterfactual uniform price or Vickrey auction. We conclude that switching from a discriminatory auction to a uniform price or Vickrey auction would not significantly increase revenue. Moreover, such a switch would increase bidder expected surplus by at most 0.02 percent.

E-Commerce and the Market Structure of Retail Industries

This article examines the effect of the advent and diffusion of e-commerce on supply-side industry structure. We specify a general industry model involving consumers with differing search costs buying products from heterogeneous producers. We interpret e-commerce as a reduction in consumers’ search costs. We show how it reallocates market shares from high-cost to low-cost producers. We test the model using US data for three industries: travel agencies, bookstores and new car dealers. Each industry exhibits the market share shifts predicted by the model but the mechanisms vary, ranging from aggregate factors in the travel industry to local-market factors in the other two industries.

Network structure of production

Complex social networks have received increasing attention from researchers. Recent work has focused on mechanisms that produce scale-free networks. We theoretically and empirically characterize the buyer–supplier network of the US economy and find that purely scale-free models have trouble matching key attributes of the network. We construct an alternative model that incorporates realistic features of firms’ buyer–supplier relationships and estimate the model’s parameters using microdata on firms’ self-reported customers. This alternative framework is better able to match the attributes of the actual economic network and aids in further understanding several important economic phenomena.

The Determinants of Bank Mergers: A Revealed Preference Analysis

We provide new estimates of merger value creation by exploiting revealed preferences of merging banks within a matching market framework. We find that merger value arises from cost efficiencies in overlapping markets, relaxing of regulation, and network effects exhibited by the acquirer-target matching. Beyond our findings, the revealed preference method has notable advantages that warrant its application beyond the bank merger market. Notably, we show that the method outperforms reduced form alternatives out of sample, enables sensible counterfactual experiments, and can be used to evaluate private-to-private mergers, which have been understudied because of lack of stock market data.Data, as supplemental material, are available at http://dx.doi.org/10.1287/mnsc.2015.2245 . This paper was accepted by Amit Seru, finance .

Advertising, Consumer Awareness, and Choice: Evidence from the U.S. Banking Industry

How does advertising influence consumer decisions and market outcomes? We utilize a detailed data set on consumer shopping behavior and choices over retail bank accounts to investigate the effects of advertising on the different stages of the shopping process: awareness, consideration, and choice. We formulate a structural model in which advertising is allowed to affect each of the separate stages of decision-making. The model endogenizes consumers’ choices of consideration sets by positing that consumers undertake costly search. Our results indicate that advertising in the U.S. banking market is primarily a shifter of awareness as opposed to consideration or choice. Advertising makes consumers aware of more options; thus consumers search more and find better alternatives than they would otherwise. In turn, this increases the market share of smaller banks making the U.S. banking industry more competitive.

Search with Learning

This paper provides a method to estimate search costs in an environment in which consumers are uncertain about the price distribution. Consumers learn about the price distribution by Bayesian updating their prior beliefs. The model provides bounds on the search costs that can rationalize observed search and purchasing behavior. Using individual-specific data on web browsing and purchasing behavior for electronics sold online we show how to use these bounds to estimate search costs. Estimated search costs are sizable and are found to relate to consumer characteristics in intuitive ways. The model outperforms a standard sequential search model in which the price distribution is known to consumers.

Search With Learning for Differentiated Products: Evidence from E-Commerce

This article provides a method to estimate search costs in a differentiated product environment in which consumers are uncertain about the utility distribution. Consumers learn about the utility distribution by Bayesian updating their Dirichlet process prior beliefs. The model provides expressions for bounds on the search costs that can rationalize observed search and purchasing behavior. Using individual-specific data on web browsing and purchasing behavior for MP3 players sold online we show how to use these bounds to estimate search costs as well as the parameters of the utility distribution. Our estimates indicate that search costs are sizable. We show that ignoring consumer learning while searching can lead to severely biased search cost and elasticity estimates.

Crisis Management: Analyzing Default Risk and Liquidity Demand during Financial Stress

This paper explores the reliability of using prices of credit default swap contracts (CDS) as indicators of default probabilities during the 2007/2008 financial crisis. We use data from the Canadian financial system to show that these publicly available risk measures, while indicative of initial problems of the financial system as a whole, do not seem to correspond to risks implied by the cross-sectional heterogeneity in bank behavior in short-term lending markets. Strategies in, and reliance on the payments system as well as special liquidity-supplying tools provided by the central bank seem to be more important additional indicators of distress of individual banks, or lack thereof than the CDSs. It therefore seems that central banks should utilize high-frequency data on liquidity demand to obtain a better picture of financial health of individual participants of the financial system.This paper shows that strategies in, and reliance on the payments system as well as special liquidity-supplying tools provided by the central bank are important indicators of distress of individual banks. We conclude that central banks can benefit from using high-frequency data on liquidity demand to obtain a better picture of the financial health of individual participants of the financial system. For the particular case of Canada, using unique features of the payments system and information from the liquidity facilities we find that the willingness-to-pay for liquidity during the financial crisis stayed at low levels throughout the Canadian financial system and that there was no increase in counterparty risk. A key lesson of our analysis is that transactions-level data can be be valuable in determining the appropriate response of regulators and central banks to a financial crisis.