In search-and-matching models, the nonlinear nature of search frictions increases average unemployment rates during periods with higher volatility. These frictions are not, however, by themselves sufficient to raise unemployment following an increase in perceived uncertainty; though they may do so in conjunction with the common assumption of wages being determined by Nash bargaining. Importantly, option-value considerations play no role in the standard model with free entry. In contrast, when the mass of entrepreneurs is finite and there is heterogeneity in firm-specific productivity, a rise in perceived uncertainty robustly increases the option value of waiting and reduces job creation.

在搜索和匹配模型中，搜索摩擦的非线性性质会增加波动性较高时期的平均失业率。然而，这些摩擦本身并不足以在人们感知到的不确定性增加后导致失业率上升；尽管他们可能会结合工资由纳什讨价还价决定的普遍假设来这样做。重要的是，期权价值考虑因素在免费进入的标准模型中不起作用。相比之下，当企业家数量有限且企业特定生产率存在异质性时，感知不确定性的增加会大幅增加等待的选择价值并减少就业机会的创造。