UM MODELO PARA O ESTUDO DA DIFUSÃO DE EMISSORAS DE TELEVISÃO NAS CIDADES BRASILEIRAS UMA VERSÃO PRELIMINAR

This paper is an attempt to model the spread of broadcast television in the brazilian cities into the framework of the innovation diffusion theory. It is hypothesized that three variables account for the diffusion of broadcast television: city size, the distance from cities that already have television stations and the rank of the city in the national urban system. This is a highly schematic hypothesis and the model used for its testing is stated in a completely deterministic form: c₁ ti + c₂ di = y where where c₁ c₂ are constants, ti . is a measure of the city size, di is a distance indicator and y is the estimated possibility of adoption by city i. The repeated application of the model generates a simulated sequence to be compared to the actual sequence of adoptions. The analysis was carried out at two scales: the national and the macroregional. At the national level the estimated sequence did not fit the actual, but at the regional level the results were much better. The results seem to implie that the spread of broadcast television in Brazil is the outcome of a diffusion process, even though the model was not powerful enough to give unquestionable proof. Changes in this preliminary model are envisaged, both by modifying its deterministic form and by incorporating new variables into itr structure.