Service quality in Brazilian mobile telephony: an efficiency frontier analysis

The mobile telephony sector is characterized by the dynamic interplay of rapid changes in technology and an apparently growing competition, as indicated by the fierce nonprice competition, and is yet associated with the entry of new operating companies in some cases. In this context, a relevant and neglected issue is the assessment of how service quality responded to an increasingly competitive environment. This study utilizes data envelopment analysis to assess the quality efficiency of mobile telephony companies in Brazil during the 2000-2003 period. Window analysis was conducted for the entire period, taking as reference different quality indicators pertaining to different forms of complaints and calls completed and interrupted. The efficiency measurement was made feasible by interpreting the indicators reflecting a positive dimension of quality as outputs and those reflecting negative aspects of quality as inputs. Given potential heterogeneities across firms that relate to the frequency band and to the technology (time division multiple access technology and code division multiple access technology among others), this article considered adjusted efficiency scores. The Tobit model for censored data was estimated to control for the aforementioned aspects. Rescaled residuals from the econometric estimation produced efficiency scores for service quality. The evidence indicated an overall improvement in efficiency over time. Nonparametric tests were consistent with a positive evolution of quality over time even for shorter subperiods.