In short, although I believe that inflation expectations are critical to assessing the inflation outlook, I cannot be sure (particularly in real time) that our expectational measures are accurate and so cannot know what precise role expectations play in wage and price dynamics.
In sum, then, I found reading the paper to be useful and instructive because it reminded me not only of what we have learned but also of what we still do not know. 2  James H. Stock and Mark W. Watson (2007), "Why Has U.S. Inflation Become Harder to Forecast?" Journal of Money, Credit, and Banking, supplement to vol. 39 (February), pp. 3-33.