Machine Replacement and the Business Cycle: Lumps and Bumps
研究工厂资本存量离散变化导致的投资波动，发现设备更换周期、资本年龄分布和总体冲击相互作用产生丰富的总体投资动态，并指出忽略投资年份分布变化会导致可预测的预测误差。
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 aggregate shock. Using plant-level data, lumpy investment is procyclical and more likely for older capital. Further, the predicted path of aggregate investment that neglects vintage effects tracks actual aggregate investment reasonably well. However, ignoring fluctuations in the cross-sectional distribution of investment vintages can yield predictable nontrivial errors in forecasting changes in aggregate investment.