I develop a highly tractable general equilibrium model in which heterogeneous producers face collateral constraints, and study the effect of financial frictions on capital misallocation and aggregate productivity. My economy is isomorphic to a Solow model but with time-varying TFP. I argue that...

This paper explores investment fluctuations due to discrete changes in a plant's capital stock. The resulting aggregate investment dynamics are surprisingly rich, reflecting the interaction between a replacement cycle, the cross-sectional distribution of the age of the capital stock, and an...

The countercyclical pattern of inventory-sales ratios is a striking feature of inventory behavior. In a model where inventories are productive for sales, both the markup of price over marginal cost and expected changes in marginal cost are key determinants of that ratio. This paper argues that...

We estimate how durable expenditures respond to government spending shocks at different points in the business cycle using a nonlinear VAR approach that allows for the durable multiplier to vary smoothly with the state of the economy. We find strong evidence that the aggregate durable spending...

We estimate a state-of-the-art DSGE model to study the natural rate of interest in the United States over the last 20 years. The natural rate is highly procyclical, and fell substantially below zero in each of the last three recessions. Although the drop was of comparable magnitude across the...

When a production process requires two extremely complementary inputs, conventional wisdom holds that a firm would always upgrade them simultaneously. We show, however, that if upgrading each input involves a fixed cost, the firm may upgrade them at different dates, "asynchronously." This...

A representative-consumer model with Epstein-Zin-Weil preferences and i.i.d. shocks, including rare disasters, accords with observed equity premia and risk-free rates if the coefficient of relative risk aversion equals 3-4. If the intertemporal elasticity of substitution exceeds one, an increase...