Sources of Superior Performance: Market Share versus Industry Effects in the U.S. Brewing Industry TORIo Cynthia A Montgomery; Birger Wernerfelt Management Science, Vol 37, No &(Aug, 1991), 954-959 Stable url: http://links.jstor.org/sici?sici=0025-1909%028199108%02937%3a8%03c954%03asospms%o3e2.0.c0%03b2-a Management Science is currently published by INFORMS Your use of the jStOR archive indicates your acceptance of JSTOR,'s Terms and Conditions of Use, available at http://www.jstor.org/about/terms.htmlJstOr'sTermsandConditionsofUseprovidesinpartthatunlessyou have obtained prior permission, you may not download an entire issue of a journal or multiple copies of articles, and you may use content in the JSTOR archive only for your personal, non-commercial use. Please contact the publisher regarding any further use of this work. Publisher contact information may be obtained at http://wwwjstor.org/journals/informs.html Each copy of any part of a STOR transmission must contain the same copyright notice that appears on the screen or printed page of such transmission jStOR is an independent not-for-profit organization dedicated to creating and preserving a digital archive of scholarly journals. For more information regarding JSTOR, please contact support @ jstor. org http://www」]stor.org Wed nov204:09:10200