Ownership Unbundling of Gas Transmis- sion Networks - Theoretical Background and Empirical Evidence

In this paper we analyse empirically the effects of ownership unbundling of gas trans- mission networks on the level of end-user prices. Based on a panel out of 29 OECD countries over 18 years we apply advanced approaches like the fixed effects estimator with robust standard errors and the corrected Least Squares Dummy Variable estimator (LSDVC) by Bruno (2005). Controlling for the oil price, the GDP, structural parameters of the gas sector as well as for other regulatory variables like ownership structure, de- gree of market opening and third party access, we find no significant effect of ownership unbundling on prices. Instead, the variable for market opening shows significant influ- ence in the static as well as in the dynamic setting.