In this paper, the possibility of nonlinear dynamic adjustment in the sugar-ethanol-oil nexus in Brazil is examined. Threshold vector error correction models are employed to test for linearity in the adjustment of prices of sugar and oil, ethanol and oil and ethanol and sugar. Strong evidence of threshold type nonlinearity is found. The results suggest that sugar and oil and ethanol and oil prices are characterised by discrete threshold behaviour, whereas sugar and ethanol can be thought of as being linearly cointegrated. Threshold estimates suggest that sugar prices adjust rapidly to a long run equilibrium, determined by oil prices, in an asymmetric manner, when disequilibria are negative. The dynamic adjustment of ethanol prices is faster when the oil-ethanol price spread widens and ethanol prices are below a critical threshold. Both sugar and ethanol prices are found to be determined by oil prices and no evidence for a causal relationship that runs from oil to ethanol to sugar is found.
Part of empirical modeling - Conduct a bivariate nonlinear co integration tests using threshold Vector Error Correction (TVEC) methodology (Hansen and Seo, 2002). Need to develop Matlab code.
Download:- thresholdVectorErrorCorrection.pdf