@techreport{NBERw9728,
 title = "Product Differentiation, Search Costs, and Competition in the Mutual Fund Industry: A Case Study of the S&P 500 Index Funds",
 author = "Ali Hortacsu and Chad Syverson",
 institution = "National Bureau of Economic Research",
 type = "Working Paper",
 series = "Working Paper Series",
 number = "9728",
 year = "2003",
 month = "May",
 URL = "http://www.nber.org/papers/w9728",
}