entry costs reduction and competition in the portuguese mobile telephony industry philippe gagnepainy universidad carlos iii de madrid pedro pereiraz autoridade da concorr ncia august 2005 abstract we study e ect of on construct estimate a model that includes demand network cost equations latter accounts for ine ciency reducing ort our results suggest third operator 1998 lead to signi cant reductions fostered also show failure account leads biased estimates finally nd estimated price margins are similar hypothetical nash if rms patient have optimistic beliefs about growth key words empirical analysis jel classi cation l13 l43 l93 thank s hoernig as well participants conference tribute jean jacques la ont toulouse very useful comments ydepartamento econom c 126 28903 getafe spain mail eco uc3m es
