modelos de previsão para a exportação das principais commodities ...

ABSTRACT
This paper estimates equations for the value of exports and external price of the
main Brazilian commodities. Those commodities are: coffee, soy, sugar, iron ore,
meat, aluminum, cocoa, orange juice and tobacco, which amount to 25% of total
Brazilian exports. We estimate unrestricted Vector Autoregressions (VAR) and
restricted models in first differences. We test for the inclusion of a few exogenous
variables, namely imports of industrialised countries, the Libor rate and the real
effective exchange rate of the US dollar. Then we compare the models in terms of
forecasting capacity. We find that both for the value of exports and the external
prices the unrestricted VAR has a higher forecating accuracy, except for the value
of exports of orange juice and for prices of iron ore and cocoa.