Impacts of Prices on Brazil's Natural Rubber Exports in Four Historical Periods over 198 Years

Abstract

The objectives of the research are: a - to create a model that describes the trajectory of natural rubber exports from 1827 to 2024, with its price as an exogenous variable; b - to assess the impact of prices on the model that describes the trajectory of exports; c - to estimate the heterogeneities/homogeneities of natural rubber exports and prices in each of the four periods into which the series was divided in this study; d - to estimate the annual growth rates of natural rubber exports and prices in the four periods. The research covers annual time series of natural rubber exports and prices for the period 1827-2024. An ARIMAX model was used to describe the trajectory of Brazilian exports, with prices as exogenous variables. The research identified four historical periods: The first (1827/1878) when Brazil held a monopoly on exports and, in this position, set the prices. The second period (1879/1912), which became known as the "Rubber Cycle," when exports and prices showed the highest growth rates. During this period, there was competition from natural rubber produced in Southeast Asian countries. The third period (1913/1950) was characterized by the loss of competitiveness of Brazilian exports. In the fourth period (1951/2024), Brazil became a net importer of the commodity. The research shows the great instability of Brazilian exports and natural rubber prices in the four periods studied, the significant growth in prices and quantities exported in the "rubber cycle," as well as the significant decline in these variables in the third and fourth periods, when Brazil lost its ability to compete in the international market for this commodity.