Banking industry : Davids’ hopes facing Goliaths At the beginning of the third millennium banking integration is more and more frequent. Economies of scale seem to be the unique factor of « industrial motivity » in this sector. They play an important role in some banking businesses. But surroundings stress integration : globalisation, increase of customers’ size and the « new economy ». However, this process isn’t irreversible and banking concentration faces obstacles. This evolution must be analysed concerning each business and not each firm. So small firm can survive or expand. JEL classifications : G21Le début du troisième millénaire est marqué par une accélération des concentrations bancaires. Les économies d’échelle semblent être dev...