CG the OP,
The future is unknown so it is risky, nothing is ever guaranteed. There is risk in retirement at any age, especially ER. 4% plus inflation was only for 30 years, not ever suggested as a 40 year SWR. What you are questioning was not in the studies, just extrapolated by sloppy internet postings. Read the original studies by Wm. Bengen and the Trinity study by the Trinity professors. Read about the range and frequency of the ending portfolio balances. The Journal of Financial Planning used to have Bengen's in the free archives. I don't know what the subsciption fee is now. Reading all of Wm. Bernstein's Retirement Calculator articles is good too. Bengen's original is now 16 years old, and he no longer recommends the rigid "percentage plus inflation" SWR with no mid-stream corrections.
4% does tell the general public to have 25 multiples of expenses before starting retirement at age 65. That was new info at that time but it is still valid. Have you seen Gummy's chart of retiree maximum SWR by starting years? It shows who was lucky (early 1950s) and who was unlucky (late 1960's). It ends with 1975 retirees since he wrote it in 2005.
The future is unknown so it is risky, nothing is ever guaranteed. There is risk in retirement at any age, especially ER. 4% plus inflation was only for 30 years, not ever suggested as a 40 year SWR. What you are questioning was not in the studies, just extrapolated by sloppy internet postings. Read the original studies by Wm. Bengen and the Trinity study by the Trinity professors. Read about the range and frequency of the ending portfolio balances. The Journal of Financial Planning used to have Bengen's in the free archives. I don't know what the subsciption fee is now. Reading all of Wm. Bernstein's Retirement Calculator articles is good too. Bengen's original is now 16 years old, and he no longer recommends the rigid "percentage plus inflation" SWR with no mid-stream corrections.
4% does tell the general public to have 25 multiples of expenses before starting retirement at age 65. That was new info at that time but it is still valid. Have you seen Gummy's chart of retiree maximum SWR by starting years? It shows who was lucky (early 1950s) and who was unlucky (late 1960's). It ends with 1975 retirees since he wrote it in 2005.