The Consumer Loss of the Minimum Duration for Mobile Telephone Calls  Lukasz Grzybowski y University of Alicante Pedro Pereira z Autoridade da ConcorrŒncia July 2007 Abstract We estimate, for Portugal, the monetary loss per consumer of the existence of a minimum duration for mobile telephone calls. First, we estimate the demand for durations of calls, using individual level data and a Tobit model for panel data with individual random e/ects. The demand for duration is inelastic, and the elasticity varies across rms. At current prices, the average uncensored duration of calls ranges between 63  66 seconds, while with a minimum duration, the average duration is 101  109 seconds. The existence of a minimum duration for calls leads to a monetary loss for consumers of 35  40% of the average bill. Key Words: Mobile Telephony, Price Elasticities, Call Duration, Tobit model JEL Classication: L13, L43, L93  The opinions expressed in this article reect only the authorsviews, and in no way bind the institutions to which they are a¢ liated. y Departamento de Fundamentos del Analisis Economico, Universidad de Alicante, Campus de San Vicente, 03080 Alicante, Spain, Phone: +49 179 6662936, E-mail: lukasz@merlin.fae.ua.es z AdC, Rua Laura Alves, 1050-188 Lisboa, Portugal, e-mail: jppereira@oninetspeed.pt 1