Thanks, Larry. The glidepath research by Pfau and Kitces is similar in many respects to the "glidepath illusion" research advanced by Rob Arnott in https://www.researchaffiliates.com/Production%20content%20library/F_201… and http://papers.ssrn.com/sol3/papers.cfm?abstract_id=2326774, and later picked up in http://papers.ssrn.com/sol3/papers.cfm?abstract_id=2217406.