Convergence of European Spot Market Prices for Natural Gas? A Real-Time Analysis of Market Integration using the Kalman Filter

This paper provides a textbook example of integration between commodity markets, and the subsequent price convergence or absence thereof. We analyze price relations between spot markets for natural gas in Europe. We apply time-varying coefficient estimation applying the Kalman filter, to test whether price convergence between different locations is really taking place. Our results reveal that the construction of a pipeline between the UK and Zeebrugge (Belgium) has led to almost perfect price convergence between these locations; on the other hand, liberalization on the continent does not seem to be working yet.