Estimating the long-run equilibrium relationship: The case of city-gate and residential natural gas prices

This paper examines market cointegration of city-gate and residential natural gas prices. Cointegration of gas prices across different segments of the industry provides evidence that deregulation has resulted into a more integrated, competitive natural gas industry where gas prices converge into a long-run equilibrium. Our results indicate prices further down the distribution line, the final two points of consumption, are cointegrated for a majority of the US states post open access and retail unbundling, although we find little evidence of perfect market integration. The two price series likewise converge to the long-run equilibrium faster post open access and retail unbundling. Results relative to state level unbundling (choice programs) reveal mixed outcomes with a few states without retail unbundling exhibiting market integration while some states with full unbundling exhibiting non-cointegration.