This is from "Has the U.S. Economy Become Less Interest Rate Sensitive?," by Jonathan L. Willis and Guangye Cao of the KC Fed:
... IV. Conclusion Although monetary policy is an important tool for promoting price and economic stability, its efficacy can change over time. This article investigates the interest rate channel of monetary policy and, more specifically, the response of employment to changes in the federal funds rate. Analytical results suggest the interest sensitivity of employment has declined in recent decades for nearly all industries and for the overall economy. The article tests three possible explanations for the observed change in interest sensitivity. First, changes in the conduct of monetary policy do not appear to be responsible for the shift in interest sensitivity. Second, linkages between the short end and the long end of the yield curve along with linkages between financial markets and the overall economy have become protracted. Third, structural shifts have altered how employment changes at the industry level feed back to the aggregate economy. Overall, the findings suggest that the decline in the interest sensitivity of the economy is not due to changes in the conduct of monetary policy, but rather to structural changes in industries and financial markets. Future research should investigate whether and how monetary policy should adapt in response to these changes.