The Investment Network, Sectoral Comovement, and the Changing U.S. Business Cycle
研究发现投资品生产集中在少数“投资枢纽”行业，这些行业的特定冲击通过投资网络传导，影响总就业和劳动生产率，解释了1980年代以来美国商业周期模式的变化。
Abstract We argue that the network of investment production and purchases across sectors is an important propagation mechanism for understanding business cycles. Empirically, we show that the majority of investment goods are produced by a few “investment hubs,” which are more cyclical than other sectors. We embed this investment network into a multisector business cycle model and show that sector-specific shocks to the investment hubs and their key suppliers have large effects on aggregate employment and drive down labor productivity. Quantitatively, we find that sector-specific shocks to hubs and their suppliers account for an increasing share of aggregate fluctuations over time, generating the declining cyclicality of labor productivity and other changes in business cycle patterns since the 1980s.