This paper gives rigorous definitions of the rebound effect, not only in the well described single commodity case (Khazzoom, 1980. The Energy Journal 1(4), 21-40.), but also for a multiple commodity case. It is shown that the familiar laws for the single case do not hold for the multiple case. The paper describes the state of the art of empirical estimation of the rebound effect, with special focus on the estimates done for the Netherlands. We conclude that according to every definition, empirical evidence shows that the RE is probably small: between 0 and 15%.