Risk Premia and Variance Bounds
推导了一个比Hansen和Jagannathan（1991）更严格的方差界，并应用于代表性消费者的幂效用函数，发现消费风险溢价加剧了股权溢价之谜。
If a pricing kernel assigns a premium to a risk variable that differs from the one assigned by the minimum-variance admissible kernel, then the pricing kernel must exhibit more variability than the minimum-variance kernel. Based on this intuition, we derive a variance bound that is more stringent than that of Hansen and Jagannathan (1991). When we apply our bound to the kernel of a representative consumer with power utility, we find that the consumption risk premium increases the severity of the "equity-premium puzzle" of Mehra and Prescott (1985).