Indeterminacy, Aggregate Demand, and the Real Business Cycle

We show that under indeterminacy aggregate demand shocks are able to explain not only aspects of actual °uctuations that standard RBC models predict fairly well, but also aspects of actual °uctuations that standard RBC models cannot explain, such as the hump-shaped, trend reverting impulse responses to transitory shocks found in US output (Cogley and Nason, AER, 1995); the large forecastable movements and comovements of output, consumption and hours (Rotemberg and Woodford, AER, 1996); and the fact that consumption appears to lead output and investment over the business cycle. Indeterminacy arises in our model due to capacity utilization and mild increasing returns to scale.