Investment under Upstream and Downstream Uncertainty
研究了供应链中上游（供应商）和下游（客户）不确定性对企业投资的不同影响，发现上游不确定性抑制投资，而下游不确定性反而有扩张效应，对宏观增长和资产价格也有相反预测。
ABSTRACT The impact of uncertainty shocks on firm‐level economic activity depends on their origin in supply chains. Upstream (downstream) uncertainty from suppliers (customers) is associated with variability over future input (output) prices. Consequently, a real‐option production model with time‐to‐build suggests that only upstream uncertainty suppresses investment, since upstream (downstream) uncertainty affects the shorter (longer) run. Production network data show that upstream uncertainty negatively affects firm‐level outcomes. Conversely, downstream uncertainty affects firm‐level outcomes more weakly but positively. At the macro level, these two uncertainties oppositely predict aggregate growth and asset prices. Overall, downstream uncertainty has an expansionary effect, in contrast to other facets of uncertainty.