Canary Island Tomato Exports: A Structural Analysis of Seasonality

The European tomato market is characterised by a constant process of dynamic adjustment toward the equilibrium. Furthermore, Canary tomato exports cause a high seasonal impact on market prices in the winter period. In these circumstances, an adequate distribution of shipments throughout the campaign could contribute to maximize producers' profits. The goal of this paper is to analyse the seasonal pattern of Canary tomato exports to Europe throughout the first fourteen campaigns following Spanish integration into the European Union. These export levels show some degree of instability, clearly related to the changes in the European Union trade rules, and there is a long period, the summer, without exports. Moreover, we have opted by using weekly data. These factors should be taken into account in order to accurately capture the performance of exports and, specifically, the nature of their seasonal behaviour. Thus, this analysis is carried out inside the frame delimited by the structural approach to time series and the usefulness of spline functions as an alternative to standard seasonal variation models is shown.