The paper introduces an innovative three-step approach to simultaneously investigate the price dispersion in retail electricity and natural gas markets for both domestic and industrial consumers over time and across EU countries. In the first step, a multilateral Country-Product-Dummy price index is applied to estimate the purchasing power parity (PPP) of the EU energy market. In the second step, the PPP values are then used to cluster the EU countries by means of a hierarchical cluster analysis based on the Ward method. Finally, in the third step, the Hodrick-Prescott filter is employed to estimate the PPP trends and to investigate different notions of convergence, within and between the identified clusters. We show that different EU countries can be classified into four clusters which are characterized by CPD indexes and PPPs below, slightly below, slightly above and above the average CPD/PPP series, respectively. Taken together, the results from our analysis indicate that the electricity and natural gas prices across the EU-28 member states have not converged, despite significant efforts in market integration and regulatory harmonization. The evidence of a slow beta-convergence is not associated with sigma- and club convergence both at intra- and inter-cluster level. Among country-specific factors, the results suggest that the adoption of national energy and climate policies could have played a major role in explaining the difficulties of the convergence process at a retail price level.

本文介绍了一种创新的三步法，以同时调查随着时间的推移以及整个欧盟国家的国内和工业消费者零售电力和天然气市场的价格差异。第一步，应用多边国家-产品-虚拟价格指数来估计欧盟能源市场的购买力平价（PPP）。第二步，通过基于 Ward 方法的层次聚类分析，使用 PPP 值对欧盟国家进行聚类。最后，在第三步中，使用 Hodrick-Prescott 过滤器来估计 PPP 趋势并研究已识别集群内部和集群之间的不同收敛概念。我们表明，不同的欧盟国家可以分为四个集群，其特征在于以下 CPD 指数和 PPP，分别略低于、略高于和高于平均 CPD/PPP 系列。综上所述，我们的分析结果表明，尽管在市场整合和监管协调方面做出了重大努力，但欧盟 28 国的电力和天然气价格并未趋同。缓慢的 beta 收敛的证据与集群内和集群间级别的 sigma 和 club 收敛无关。在特定国家因素中，结果表明，国家能源和气候政策的采用可能在解释零售价格水平趋同过程的困难方面发挥了重要作用。我们的分析结果表明，尽管在市场整合和监管协调方面做出了重大努力，但欧盟 28 国的电力和天然气价格并未趋同。缓慢的 beta 收敛的证据与集群内和集群间级别的 sigma 和 club 收敛无关。在特定国家因素中，结果表明，国家能源和气候政策的采用可能在解释零售价格水平趋同过程的困难方面发挥了重要作用。我们的分析结果表明，尽管在市场整合和监管协调方面做出了重大努力，但欧盟 28 国的电力和天然气价格并未趋同。缓慢的 beta 收敛的证据与集群内和集群间级别的 sigma 和 club 收敛无关。在特定国家因素中，结果表明，国家能源和气候政策的采用可能在解释零售价格水平趋同过程的困难方面发挥了重要作用。