Recovering Costs by Increasing Market Share: An Empirical Critique of the S-Curve

An S-shaped curve relating service frequency with market share of passengers is often claimed to explain why airlines seek to increase the frequency of their services. An increase in frequency beyond some point brings about a more than proportional increase in patronage and, indirectly, in revenue. If this is the approach of airlines, however, it may prove counterproductive and instead help to explain the tendency towards excess capacity that is often seen in many airline markets. Looking at a number of major US carriers from 1990 to 2003 and their domestic market shares at several large airports there is very little evidence of the existence of any sustained S-shaped relationship; the general pattern that emerges is of a broadly linear link between frequency and market share. © 2005 LSE and the University of Bath