IDENTIFYING MOBILITY BARRIERS

This paper uses a new (PIMS) research data base to identify the mobility barriers-the factors associated with sustained intraindustry profit differentials-in a cross section of industries. The exercise suggests that differentiation-related factors play more of a role in generating intraindustry profit differentials than do cost-related ones. It also indicates that differentiation-related advantages tend to be absorbed into fatter margins and (in some instances) larger market shares, while cost-related advantages are taken primarily in the form of increases in market share.