Caves, R. E., and P. Ghemawat.
" Identifying Mobility Barriers."
Strategic Management Journal 13 (January 1992): 1-12.  also published in Strategic Management edited by Julian Birkinshaw, Northampton, MA: Edward Elgar Publishing, 2005.

The Profit Impact Market Strategy (PIMS) New Research Database is used to identify the mobility barriers (the factors associated with sustained intra-industry profit differentials) in a cross-section of industries. Data were available for all 5 years in the 1979-1983 period on 59 respondent businesses. The analysis suggests that differentiation-related factors play more of a role in generating sustained intra-industry profit differentials than do cost-related ones. It is also shown that differentiation-related advantages tend to be absorbed into bigger margins and, in some instances, larger market shares, while cost-related advantages are taken primarily in the form of increases in market share.