Airline Alliances on the north Atlantic : an analysis of traffic, market share and concentration. [Published as: The impact on traffic, market shares and concentration of airline alliances on selected European-US routes].

This paper examines the impact of airline alliances on traffic of the constituent airlines using an analysis of US Bureau of Transportation Statistics T-100 International Market Data on a monthly basis for five routes to the US from European hubs. The European hubs are Frankfurt and Paris. The period covered is January 1990–December 2003; a sufficiently lengthy period to enable the derivation of good time-series models before the ‘intervention’ of alliance formation and development. The alliances focussed on are Air France and Delta, part of the SkyTeam Alliance and Lufthansa and United Airlines, part of the Star Alliance. It is possible to distinguish code sharing agreements and then the subsequent immunity from US antitrust legislation. It is also possible to suggest some conclusions on the differences in alliance development in the more liberal open skies environments adopted by many European countries with the more traditional, stricter regulated bilaterals that exist in others such as the UK. Competition is examined using the Hirschman-Herfindahl Index so as to throw light on the impact of alliances on market concentration by route.