Modern Economy, 2017, 8, 946-958 http://www.scirp.org/journal/me ISSN Online: 2152-7261 ISSN Print: 2152-7245 DOI: 10.4236/me.2017.87066 July 26, 2017 Convergence of Energy Intensity in OECD Countries Cem Canel 1 , Selahattin Guris 2 , Burak Guris 2 , Begüm Öktem 3 , Recep Oktem 3 1 Department of Analytics, Information Systems and Supply Chain, University of North Carolina Wilmington, Wilmington, USA 2 Department of Econometrics, Faculty of Economics, Marmara University, Istanbul, Turkey 3 Department of Accounting and Tax Implications, Marmara University, Istanbul, Turkey Abstract This paper investigates whether there is energy intensity convergence in the Organization for Economic Cooperation and Development (OECD) countries or not by using annual data from the 1980-2011 period. OECD countries are Australia, Austria, Belgium, Canada, Chile, Denmark, Finland, France, Ger- many, Greece, Ireland, Italy, Japan, North Korea, South Korea, Luxembourg, Mexico, Netherlands, New Zealand, Norway, Portugal, Spain, Sweden, Swit- zerland, Turkey, UK, and USA. Energy intensity is measured by the ratio of total energy consumption to total output. Energy intensity measures the energy consumption of an economy and its overall energy efficiency. We used linear and nonlinear unit root tests from the recent literature to accomplish this goal. An analysis of the test results shows that there is no convergence in Chile, Finland, Greece, Ireland, South Korea, Luxembourg, Mexico, Nether- lands, New Zealand, Portugal, Spain, Sweden, Switzerland, and the UK. These countries should start implementing changes to their energy policies to achieve effective energy use. Keywords Energy Intensity, Nonlinear Unit Root Tests 1. Introduction Energy intensity is measured by the ratio of total energy consumption to total output, measured as Gross Domestic Product (GDP). It measures the energy consumption of an economy and its overall energy efficiency. High energy intensities indicate a high price or cost of converting energy into GDP. Low energy intensity indicates a lower price or cost of converting energy into GDP. This ratio is a measurement used in the comparison of the countries in this How to cite this paper: Canel, C., Guris, S., Guris, B., Öktem, B. and Oktem, R. (2017) Convergence of Energy Intensity in OECD Countries. Modern Economy, 8, 946-958. https://doi.org/10.4236/me.2017.87066 Received: June 17, 2017 Accepted: July 23, 2017 Published: July 26, 2017 Copyright © 2017 by authors and Scientific Research Publishing Inc. This work is licensed under the Creative Commons Attribution International License (CC BY 4.0). http://creativecommons.org/licenses/by/4.0/ Open Access