My first task in developing support for this interpretation was to see whether the economic history of the United States can be viewed as a series of what I will call productivity cycles – meaning relatively long periods of higher and then lower productivity growth.
If this is possible, then I can examine these cycles for regularities related to investment booms and equity price surges, followed by retrenchments in investment and corrections in equity values. I should note that whenever I come up with difficult assignments like this, I immediately turn to our staff to do the heavy lifting and, as usual, they didn't disappoint.