Abstract EN:

After domestic air transportation was deregulated in the united states, the american air carriers have turned their networks into hub-and-spoke systems. The american case study reveals that the economic mechanisms at the basis of such systems are the scale and scope economies typical of air transport, as well as the competition between the airlines. The liberalisation of intra-european air transport requires the full understanding of these mechanisms : are intra-european hub-and-spoke networks liable to develop and be as strong a configuration as it is in the usa? all the european national air carriers are already based at a "natural hub", but the operations there do not always look like those at the american hubs. On the other hand, the current evolution seems to favour the hypothesis of the growth of hubbing within europe. A duopoly model is built to test this hypothesis. It is a two-stage game, in routing pattern and price, each sub-game being of complete but imperfect information. It produces conditions, in terms of origin-destination traffic and market length, at which a hub-and-spoke network should be economically viable. These conditions also show that such networks are liable to constitute a generalised configuration at equilibrium only if the equilibrium on some markets is a mixed-strategy equilibrium. This result can be interpreted in two different but complementary ways. This configuration may either be fundamentally unstable, or it can be one of the best replies of each firm when faced with uncertainty about its rival's choice. The lack of adequate statistics prevents any application of the model to europe. Its results have nevertheless been compared with the available data. Owing to this comparison, the relevance of the model has been tested, using popper's criterion of falsifiability. The model was also used as a framework in which the european perspectives of future network configurations have been qualitatively appreciated.