@techreport{NBERr0368,
 title = "Factor Prices May Be Constant but Factor Returns Are Not",
 author = "David F. Bradford",
 institution = "National Bureau of Economic Research",
 type = "Working Paper",
 series = "Reprint Series",
 number = "368",
 year = "1983",
 month = "May",
 URL = "http://www.nber.org/papers/r0368",
 abstract = {},
}