A Q-theory model with lumpy investment

We present an analytically tractable dynamic stochastic general equilibrium model that incorporates micro-level fixed and convex adjustment costs. We provide an explicit characterization of equilibrium dynamics by a system of nonlinear stochastic difference equations. We provide general conditions under which our model features investment lumpiness at the microeconomic level, but aggregate dynamics are isomorphic to those in a Q-theory model without fixed costs. This theoretical result is independent of the specification of the fixed cost distribution and also holds true when firms face persistent idiosyncratic productivity shocks. Copyright Springer-Verlag Berlin Heidelberg 2014