In rich, developed nations, if we improve the efficiency of end-use consumer energy services, like cars, home heating and cooling, or appliances, the literature indicates that direct rebound effects are typically on the scale of 10 to 30 percent of the initial energy savings. Additional indirect and macroeconomic effects may mean total rebound erodes roughly one-quarter to one-half of expected energy savings.22 Rebound is smallest in cases when demand for the energy service in question is already saturated (that is, we use as much of it as we would care to use), and highest in cases where the cost of the energy service is a key constraint on fulfilling demand for that service.