During the last three decades, following closely the developments in econometric theory, energy and environmental economists have empirically examined the energy-income nexus for different countries and time periods. However, today, in spite of the growing interest in this area, the state of knowledge is still controversial and unsettled. This viewpoint paper attempts to highlight some of the issues related to the existing literature on the long-run relationship and causality between energy consumption and economic growth. In particular, it discusses how it is difficult to make policy recommendations on the basis of inconsistent and conflicting results in the published literature on the subject. In order to do so, the paper first illustrates the increasing trend in the number of studies published in this area providing also a brief comparison of the conventional methods used to estimate the energy-income nexus. It then deals with new directions and different viewpoints on the same issue. (C) 2008 Elsevier Ltd. All rights reserved.