Supply chain disturbances can lead to substantial increases in production costs. To mitigate these risks, firms may take steps to reduce their reliance on volatile suppliers. We construct a model of endogenous network formation to investigate how these decisions affect the structure of the production network and the level and volatility of macroeconomic aggregates. When uncertainty increases in the model, producers prefer to purchase from more stable suppliers, even though they might sell at higher prices. The resulting reorganization of the network tends to reduce macroeconomic volatility, but at the cost of a decline in aggregate output. The model also predicts that more productive and stable firms have higher Domar weights—a measure of their importance as suppliers—in the equilibrium network. We provide a basic calibration of the model using U.S. data to evaluate the importance of these mechanisms.

We formalize the editorial role of news media in a multisector economy and show that media can be an independent source of business cycle fluctuations, even when they report accurate information. Public reporting about a subset of sectoral developments that are newsworthy but unrepresentative causes firms across all sectors to hire too much or too little labor. We construct historical measures of US sectoral news coverage and use them to calibrate our model. Time-varying media focus generates demand-like fluctuations that are orthogonal to productivity, even in the absence of non-TFP shocks. Presented with historical sectoral productivity, the model reproduces the 2009 Great Recession.