Rockets and feathers behaviour in the Spanish gasoline and diesel market: New evidence

In this paper we analyse the potential asymmetric response of retail prices for gasoline and diesel-fuel to changes in oil prices for the Spanish economy and its relation with the so-called 'rockets and feathers' behaviour. We show that the assumption made by previous studies, which use as the key explanatory variable the sign -positive or negative- of the change in international oil prices, is inadequate for the Spanish case and the magnitude of the change in international oil prices is also relevant. For small changes in international oil prices there is neither price asymmetry nor rockets and feathers behavior in the retail markets. However, price asymmetries in line with rockets and feathers behavior in retail gasoline and gasoil markets are present when these changes exceed a certain threshold. Following Martin-Moreno et al. (2018) we first apply an Auto-regressive Error Correction Model and endogenously estimate the threshold triggering the rockets and feathers behaviour. A time-varying nature for the dynamic response of retail prices to oil price shocks is revealed when we estimate the TAR-ECM model using rolling windows. Hence, in a second stage, we use a Markov-switching estimation of the model to test the robustness of the results given its suitability to changing environments. This study could have relevant policy implications for the Spanish gasoline and gasoil retail markets due to the ongoing debate on the existence of a rockets and feathers behavior in gasoline and gasoil retail markets between the Spanish regulatory body and the oil companies.