Modelling the Cyclical Behaviour of Wine Production in the Douro Region Using a Time-Varying Parameters Approach

This paper investigates the cyclical behaviour of the wine production in Portugal’s Douro region during the period of 1932 to 2008. In general, wine production is characterised by large fluctuations. These fluctuations may cover the existence of deterministic cycles. Hence, in this paper, we decompose the wine production’s variance in order to find the dominating production cycles In the next step we try to explain those cycles using a dependent variable, namely the medium spring temperature for the period 1967 to 2008. We estimated a Time-Varying Autoregressive Model, which could explain 76% of wine variability (R2=0.76; n=69; p