"One basic problem in business-cycle studies is how to deal with nonstationary time series. The market economy is an evolutionary system. Economic time series therefore contain stochastic components that are necessarily time dependent. Traditional methods of business cycle analysis, such as the...

"When monetary policies are endogenous, the conventional VAR approach for detecting the effect of monetary policies is powerless. This paper proposes to test the implication of monetary policies along a different dimension. That implication is to exploit the policy induced exogeneity of...

"Price rigidity is the key mechanism for propagating business cycles in traditional Keynesian theory. Yet the New Keynesian literature has failed to show that sticky prices by themselves can effectively propagate business cycles in general equilibrium. We show that price rigidity in fact can (by...

We endogenize the liquidity and the quality of private assets in a tractable incomplete-market model with heterogeneous agents. The model decomposes the convenience yield of government bond into a "liquidity premium" (flight to liquidity) and a "safety premium" (flight to quality) over the...