@techreport{NBERw10577,
 title = "Why Barriers to Entry are Barriers to Understanding",
 author = "Dennis W. Carlton",
 institution = "National Bureau of Economic Research",
 type = "Working Paper",
 series = "Working Paper Series",
 number = "10577",
 year = "2004",
 month = "June",
 URL = "http://www.nber.org/papers/w10577",
 abstract = {This paper discusses and criticizes the usual definitions of barriers to entry.  The failure of the concept of barrier to entry to incorporate a time dimension means that it is a concept that is in need of additional embellishment in order to be useful in a practical problem or for antitrust or regulatory proceedings.},
}