Imperfect Competition and Indeterminacy of Aggregate Output

This paper shows imperfect competition can lead to indeterminacy in aggregate output in a standard DSGE model with imperfect competition. Indeterminacy arises in the model from the composition of aggregate output. In sharp contrast to the indeterminacy literature pioneered by Benhabib and Farmer [3] and Gali [19], indeterminacy in our model is global; hence it is more robust to structural parameters. In addition, sunspots in our model can be autocorrelated. The paper provides a justification for exogenous variations in desired markups, which play an important role as a source of cost-push shocks in the monetary policy literature. Our model outperforms a standard RBC model driven by technology shocks in several dimensions, including the volatility of labor market and the hump-shaped output dynamics