We develop a business cycle model in which consumption goods, physical capital, and human capital are produced in separate sectors. An important feature of the model is that human and machine inputs in the production process are treated symmetrically: each has both a stock and flow component....

We employ a neoclassical business-cycle model to study two sources of business-cycle fluctuations: marginal efficiency of investment shocks, and total factor productivity shocks. The parameters of the model are estimated using a Bayesian procedure that accommodates prior uncertainty about their...