Analysis of long-term natural gas contracts with vine copulas in optimization portfolio problems
In Europe gas is sold according to two main methods: long-term contract (LTCs) and hub pricing. Europe is moving towards a mix of long term and spot markets, but the eventual outcome is still unknown. The fall of the European gas demand combined with the increase of the US shale gas exports and the rise of Liquefied Natural Gas availability on international markets have led to a reduction of the European gas hub prices. On the other side, oil-indexed LTCs failed to promptly adjust their positions, implying significant losses for European gas mid-streamers that asked for a re-negotiation of their existing contracts and obtained new contracts linked also to hub spot prices. The debate over the necessity of the oil-indexed pricing is still on-going. The supporters of the gas-indexation state that nowadays the European gas industry is mature enough to adopt hub-based pricing system. With the aim of analyzing this situation and determining whether oil-indexation can still be convenient for the European gas market, we consider both spot gas prices traded at the hub and oil-based commodities as possible underlyings of the LTCs. We investigates the dependence risk and the optimal resource allocation of the underlying assets of a gas LTC through pair-vine copulas and portfolio optimization methods with respect to five risk measures. Our results show that European LTCs will most likely remain indexed to oil-based commodities, even though a partial dependence on spot hub prices is conceded.
KeywordsLong-term natural gas contracts Multivariate dependence structure Pair-copula construction Portfolio optimization Vine copulas
We are grateful to the Editor and the anonymous referees for valuable comments. The work of the author M.E. De Giuli has been partially supported by MIUR, Italy, PRIN MISURA 2010RHAHPL. E. Allevi and G. Oggioni are grateful to the UniBS H&W Project “Brescia 20-20-20” for the financial support.
- Aas, K., Czado, C., Frigessi, A., & Bakken, H. (2009). Pair-copula constructions of multiple dependence. Insurance: Mathematics and Economics, 44, 182–198.Google Scholar
- Accioly, R. M. S., & Aiube, F. A. L. (2008). Analysis of crude oil and gasoline prices through copulas. Cadernos do IME- Série Estatìstica, 24, 5–28.Google Scholar
- Chyong, C.-K. (2015). Markets and long-term contracts: The case of Russian gas supplies to Europe. EPRG working paper (p. 1524).Google Scholar
- Czado, C., Min, A., Baumann, T., & Dakovic, R. (2009). Pair-copula constructions for modeling exchange rate dependence. Preprint available at https://mediatum.ub.tum.de/1079184. Accessed Nov 2016.
- Franza, L. (2014). Long-term gas import contracts in Europe. In CIEP paper (Vol. 8). Available at http://www.clingendaelenergy.com/inc/upload/files/Ciep_paper_2014-08_web_1.pdf. Accessed Nov 2016.
- Frisch, M. (2010). Current European gas pricing problems: Solutions based on price review and price reopener provisions. In International energy law and policy research paper series, no. 3.Google Scholar
- GIIGNL. (2018). The LNG industry. Available at https://giignl.org/publications#webform-client-form-1161. Accessed April 2018.
- Grégoire, V., Genest, C., & Gendron, M. (2008). Using copulas to model price dependencies in energy markets. Energy Risk, 5, 58–64.Google Scholar
- Heather, P., & Petrovich, B. (2017). European traded gas hubs: An updated analysis on liquidity, maturity and barriers to market integration. In The Oxford Institute for energy studies paper-energy insight (Vol. 13).Google Scholar
- Hofert, M., Kojadinovic, I., Maechler, M., & Yan, J. (2017). Package copula. Available http://copula.r-forge.r-project.org/. Accessed April 2018.
- IEA (International Energy Agency). (2013). Developing a natural gas trading hub in Asia-obstacles and opportunities. Available https://www.iea.org/publications/freepublications/publication/AsianGasHub_FINAL_WEB.pdf. Accessed Nov 2016.
- Joe, H. (1996). Families of m-variate distributions with given margins and m(m-1)/2 bivariate dependence parameters. In IMS lecture notes (Vol. 76, pp. 359–376).Google Scholar
- Markowitz, H. (1952). Portfolio selection. The Journal of Finance, 7(1), 77–91.Google Scholar
- Melling, A. J. (2010). Natural gas pricing and its future-Europe ad the battleground. Carnegie Endowment for international peace. Available at http://carnegieendowment.org/files/gas_pricing_europe.pdf. Accessed Nov 2016.
- Morales-Nápoles, O. (2010). Counting vines. In D. Kurowicka & H. Joe (Eds.), Dependence modeling: Vine copula handbook (pp. 189–218). World Scientific.Google Scholar
- Nelsen, R. B. (1999). An introduction to copulas. In Lecture notes in statistics (Vol. 139). New York: Springer.Google Scholar
- Schepsmeier, U. (2016). A goodness-of-fit test for regular vine copula models. Econometric Reviews. https://doi.org/10.1080/07474938.2016.1222231.
- Schepsmeier, U., Stoeber, J., Brechmann, E. C., Graeler, B., Nagler, T., & Erhardt, T. (2018). vineCopula: Statistical inference of vine copulas. Available at http://CRAN.R-project.org/package=vineCopula. Accessed April 2018.
- Sklar, M. (1959). Fonctions de répartition á ndimensions et leurs marges. Publications de l’Institut de Statistique de l’Université de Paris, 8, 229–231.Google Scholar
- Stern, J., & Rogers, H. V. (2014). The dynamics of a liberalised European gas market: Key determinants of hub prices, and roles and risks of major players. In The Oxford Institute for energy studies (Vol. 94). Available at http://www.oxfordenergy.org/wpcms/wp-content/uploads/2014/12/NG-94.pdf. Accessed Nov 2016.
- Theisen, N. (2014). Natural gas pricing in the EU: From oil-indexation to a hybrid pricing system. Regional Centre for energy policy research. Available at http://rekk.hu/downloads/projects/2014_rekk_natural%20gas%20pricing.pdf. Accessed Nov 2017.
- Yafimava, K. (2014). Outlook for the long term contracts in a globalizing market (focus on Europe). Presentation available at http://www.unece.org/fileadmin/DAM/energy/se/pp/geg/gif5_19Jan2015/s1_1_Yafimava.pdf. Accessed Nov 2016.