Decoupling economic growth from energy use: The role of energy intensity in an endogenous growth model
构建了一个内生经济增长理论，将能源视为机器的互补品，发现若新产品能源强度以恒定正速率下降，则可在有限能源下实现持续增长；但若存在能源强度下限，则无法实现总量脱钩。
We develop a theory of endogenous economic growth with explicit consideration of energy in the production process. Following basic thermodynamic considerations, energy is modeled as a (perfect) complement to machines. Long-run economic growth is driven by expanding product varieties. While energy flows on Earth are currently abundant, extrapolation of past consumption trends suggests that energy supply might be a binding constraint in a few centuries to millennia. We show that constant economic growth with bounded energy use is possible if the energy intensity of newly developed products declines at a constant, positive, and arbitrarily small rate. Hence, aggregate decoupling is possible even when no decoupling at the product level is possible. Aggregate decoupling is, however, not possible if there exists a strictly positive lower bound for the energy intensity of newly invented products. We further show that increasing energy prices decrease growth rates by reducing the incentive to innovate. Our results suggest that the energy intensity of structural change is decisive for future growth.