Energy consumption and greenhouse emissions across many countries have increased over time despite widespread energy efficiency improvements. One explanation offered in the literature is the rebound effect (RE), however there is a debate about its magnitude and the appropriate model for estimating it. Using a combined stochastic frontier analysis (SFA) and two-stage dynamic panel data approach, we explore these two issues of magnitude and model for 55 countries over the period 1980 to 2010. Our central estimates indicate that in the short-run, 100% energy efficiency improvement is followed by 90% rebound in energy consumption, but in the long-run it leads to a 136% decrease in energy consumption. Overall, our estimated cross-country RE magnitudes indicate the need to consider or account for RE when energy forecasts and policy measures are derived from potential energy efficiency savings.