Price and volatility dynamics between electricity and fuel costs: Some evidence for Spain

The purpose of this study is to investigate the causal linkages between the Spanish electricity, Brent crude oil and Zeebrugge (Belgium) natural gas 1-month-ahead forward prices. Following Lutkepohl et al. (2004), we control for the presence of a structural change in the series and then we use the Johansen cointegration test and a vector error correction model (VECM) to embrace the analysis. Additionally, a multivariate generalized autoregressive conditional heteroskedastic (GARCH) model is applied to explore volatility interactions between the three markets involved in the study. Our findings reveal that Brent crude oil and Zeebrugge natural gas forward prices play a prominent role in the Spanish electricity price formation process. Furthermore, causation, both in price and volatility, runs from Brent crude oil and natural gas forward markets to the Spanish electricity forward market. These results are of practical importance for both the wholesale and retail markets' participants as well as the regulator through the established link between the forward contracts' price and the Spanish tariff of last resort paid by more than 23 million of customers.