Energy efficiency-related “rebound effects” usually refer to the tendency of most consumers to increase their use of energy services in response to efficiency measures that have reduced their energy costs. This phenomenon is one reason why energy efficiency policies often result in lower energy savings than engineering-based estimates predict. Rebound effects have been the subject of intense debate in the field of energy efficiency policy for many years. In the past, the focus of this debate has been on the perceived loss of the expected energy savings and related benefits resulting from the rebound effects. However, more recently, there has been a growing recognition that policymakers need to consider the health, economic and other non-energy benefits that often result from the increase in energy services represented by user “rebound effects”. This Policy Brief, prepared by Lawrence Berkeley National Laboratory, presents an overview of the rebound effect phenomenon.