The Decline in US Potential Growth Rate

Bloomberg piece - The U.S. Economy's Top Speed Has Probably Been Overestimated for Years

http://www.bloomberg.com/news/articles/2015-07-30/the-u-s-economy-s-top-speed-has-probably-been-overestimated-for-years

Following another round of revisions (will they ever end?), US GDP growth rate appears to have averaged just 2.2% in recent years:

http://blogs.wsj.com/economics/2015/07/30/the-worst-expansion-since-world-war-ii-was-even-weaker/