- 30% Equities (S&P 500)
- 70% Fixed income (10 yr Treasuries)
- Inflation-adjusted withdrawals (linear, and with zero ending balance)
- Looking within any 40 year span since 1926
This sounds like a job for Nisiprius.

Thanks!
Thank you! I'll try to find that page on ERN's website.
Sure, that's your CAGR, but that's not what you can spend, that doesn't take into effect how your withdrawals during highs and lows have a different impact on your return.Cheego wrote: ↑Mon Sep 18, 2023 12:18 pm Your 3.03%... is that inflation-adjusted?
I used FiCalc and found the worst 40 year span was from 1940 through 1979. It shows a geometric mean (CAGR) real return on equities at 5.72% and on bonds at 0.00%. With some caveman math and their output, I calculate a net real return of a 30/70 AA at 1.72%.
Interesting. Thanks.Patzer wrote: ↑Mon Sep 18, 2023 4:57 pm3.03% is Inflation Adjusted Safe Withdrawal Rate.Cheego wrote: ↑Mon Sep 18, 2023 12:18 pm Your 3.03%... is that inflation-adjusted?
I used FiCalc and found the worst 40 year span was from 1940 through 1979. It shows a geometric mean (CAGR) real return on equities at 5.72% and on bonds at 0.00%. With some caveman math and their output, I calculate a net real return of a 30/70 AA at 1.72%.
That means that in the WORST situation, you could spend 3.03% of your initial retirement sum, inflation adjusted over 40 years and it would be 40 years before you ran out of money.
Jack Bogle's Words of Wisdom: "No analysis of the past, no matter how painstaking, assures future superiority."
Thank you, but I'm looking for the worst return over any historical 40 year span.zie wrote: ↑Mon Sep 18, 2023 8:32 pm 2022 was a tough year for bonds, one of the worst ever recorded.
AOK invests at a 30/70 AA, and in PortfolioVisualizer, you can see a Worst Year of -14.16% and a max drawdown of -17.55% However AOK doesn't strictly meet your definition, as it's total bond and not US treasuries, and the 30% equities is global equities, not the S&P 500.
Using strictly your definition, we can look up VFINX(S&P500) and VGIT(Intermediate Treasuries) and get Worst Year of -12.84% and Max Drawdown of -15.20%
I and many others used to tell people a 30/70 AA could expect a max drawdown of 15% or so. Now we know it's probably more like 20%.
Ah, I missed that. You can do it yourself with the Simba backtesting spreadsheet I imagine.Cheego wrote: ↑Mon Sep 18, 2023 8:48 pmThank you, but I'm looking for the worst return over any historical 40 year span.zie wrote: ↑Mon Sep 18, 2023 8:32 pm 2022 was a tough year for bonds, one of the worst ever recorded.
AOK invests at a 30/70 AA, and in PortfolioVisualizer, you can see a Worst Year of -14.16% and a max drawdown of -17.55% However AOK doesn't strictly meet your definition, as it's total bond and not US treasuries, and the 30% equities is global equities, not the S&P 500.
Using strictly your definition, we can look up VFINX(S&P500) and VGIT(Intermediate Treasuries) and get Worst Year of -12.84% and Max Drawdown of -15.20%
I and many others used to tell people a 30/70 AA could expect a max drawdown of 15% or so. Now we know it's probably more like 20%.
Thanks for that https://earlyretirementnow.com/safe-wit ... te-series/ website and spreadsheet pointer. I was surprised to see it included gold monthly data as well. I wouldn't count gold as gold pre 1934 however, as money was gold/silver back then (gold standard) and many might have deposited that money (gold) in return for interest (more gold/silver). Adjusting to account for that (gold=cash interest pre 1934), and moving bond risk over to the stock side, 50/50 stock/goldPatzer wrote: ↑Sun Sep 17, 2023 10:17 am Testing monthly periods starting with Jan 1926-Jan 1966 and ending with Aug 1983-Aug 2023.
For 30/70
The worst result was 3.03% and came from retiring on Feb 28th, 1946. The average result 4.37%
Worst Result by Decade:
1920s: 4.41% (Only 1926-1929)
1930s: 3.14%
1940s: 3.03%
1950s: 3.47%
1960s: 3.33%
1970s: 3.77%
1980s: 6.71% (Only 1980-1983)
You picked a pretty bad allocation!!
If you did 50/50.
The worst result was 3.50% and came from retiring on Nov 30th, 1965. The average result is 5.17%
Worst Result by Decade:
1920s 4.19% (Only 1926-1929)
1930s 3.76%
1940s 3.98%
1950s 3.99%
1960s 3.50%
1970s 3.97%
1980s 8.02% (Only 1980-1983)
How did I do the math?
The Early Retirement Now website has a spreadsheet as part of their Safe Withdrawal Series that lets you calculate data like this.
I have taken that spreadsheet and over the last few years highly customized it and vastly expanded the data, so I can calculate almost any scenario pretty much instantly.![]()
Even the original spreadsheet there would give you pretty close to what you want, if you want to run the numbers yourself.
Isn't that because for any year before 1973 the Simba spreadsheet simply uses a mix of LT, IT, and ST Treasuries to (very crudely) simulate TBM? In other words, "TBM" in said spreadsheet before 1973 isn't really "total" bond market at all. Of course the SWR would be very close to an intermediate maturity Treasury; the "TBM" in the spreadsheet is made up of a broad range of Treasuries but no other types of bonds (unlike the real TBM).martincmartin wrote: ↑Tue Sep 19, 2023 9:56 am Using intermediate term treasuries from the Simba spreadsheet, in place of Total Bond Market, changes the 100% SWR from 3.25% (TBM) to 3.24% (ITT). Same worst & second worst starting years (1937 & 1940).
One, what interest rate did you use for pre-1934? Commercial paper rates are too high before about 1922/1923 (or maybe even 1924) vs what would've been earned on an actual risk-free asset (can show proof of this if you want); before the early to mid-1920s commercial paper did carry at least some default risk/late payment risk and the rates on it reflected this to a degree. FWIW I have looked at the commercial paper rates used in the simba/Siamond bond returns simulator spreadsheet and they seem to overstate returns on what could've been achieved on a true risk free instrument (or at least the closest thing to it before Treasury Bills came along) by anywhere from maybe 55-60 basis points to 120 or 130 basis points (it varies by year).seajay wrote: ↑Tue Sep 19, 2023 10:06 amThanks for that https://earlyretirementnow.com/safe-wit ... te-series/ website and spreadsheet pointer. I was surprised to see it included gold monthly data as well. I wouldn't count gold as gold pre 1934 however, as money was gold/silver back then (gold standard) and many might have deposited that money (gold) in return for interest (more gold/silver). Adjusting to account for that (gold=cash interest pre 1934), and moving bond risk over to the stock side, 50/50 stock/goldPatzer wrote: ↑Sun Sep 17, 2023 10:17 am Testing monthly periods starting with Jan 1926-Jan 1966 and ending with Aug 1983-Aug 2023.
For 30/70
The worst result was 3.03% and came from retiring on Feb 28th, 1946. The average result 4.37%
Worst Result by Decade:
1920s: 4.41% (Only 1926-1929)
1930s: 3.14%
1940s: 3.03%
1950s: 3.47%
1960s: 3.33%
1970s: 3.77%
1980s: 6.71% (Only 1980-1983)
You picked a pretty bad allocation!!
If you did 50/50.
The worst result was 3.50% and came from retiring on Nov 30th, 1965. The average result is 5.17%
Worst Result by Decade:
1920s 4.19% (Only 1926-1929)
1930s 3.76%
1940s 3.98%
1950s 3.99%
1960s 3.50%
1970s 3.97%
1980s 8.02% (Only 1980-1983)
How did I do the math?
The Early Retirement Now website has a spreadsheet as part of their Safe Withdrawal Series that lets you calculate data like this.
I have taken that spreadsheet and over the last few years highly customized it and vastly expanded the data, so I can calculate almost any scenario pretty much instantly.![]()
Even the original spreadsheet there would give you pretty close to what you want, if you want to run the numbers yourself.
4% SWR was supported over nearly all 30 year periods since 1871 (monthly granularity).
Seen as a reserve for opportunistic purchases and gold had a historic tendency to move counter-cycle to stocks over multiple years. When stocks were down -25% so gold might have been up +33% and vice versa. If at such times you migrated gold into 'cheap' stocks at some point during the 30 years then you ended up with more shares being held than had you lumped into stocks alone at the start, and where around two-thirds of those shares were bought at a -25% discount. Both your risk of a early years bad sequence of returns risk was reduced, whilst the mid/longer term prospects were ... (very) good.
I built my spreadsheet a few years ago, and I remember that I didn't like ERN's data from that far back, so I went back and pulled old scans of New York newspapers, which if I am remembering right published an interest rate in them from the Federal Reserve Bank of New York, which I use as a proxy for the modern Fed Funds Rate or 3-Month T-Bills.Alpha4 wrote: ↑Tue Sep 19, 2023 12:02 pmOne, what interest rate did you use for pre-1934? Commercial paper rates are too high before about 1922/1923 (or maybe even 1924) vs what would've been earned on an actual risk-free asset (can show proof of this if you want); before the early to mid-1920s commercial paper did carry at least some default risk/late payment risk and the rates on it reflected this to a degree. FWIW I have looked at the commercial paper rates used in the simba/Siamond bond returns simulator spreadsheet and they seem to overstate returns on what could've been achieved on a true risk free instrument (or at least the closest thing to it before Treasury Bills came along) by anywhere from maybe 55-60 basis points to 120 or 130 basis points (it varies by year).Patzer wrote: ↑Sun Sep 17, 2023 10:17 am Testing monthly periods starting with Jan 1926-Jan 1966 and ending with Aug 1983-Aug 2023.
For 30/70
The worst result was 3.03% and came from retiring on Feb 28th, 1946. The average result 4.37%
Worst Result by Decade:
1920s: 4.41% (Only 1926-1929)
1930s: 3.14%
1940s: 3.03%
1950s: 3.47%
1960s: 3.33%
1970s: 3.77%
1980s: 6.71% (Only 1980-1983)
You picked a pretty bad allocation!!
If you did 50/50.
The worst result was 3.50% and came from retiring on Nov 30th, 1965. The average result is 5.17%
Worst Result by Decade:
1920s 4.19% (Only 1926-1929)
1930s 3.76%
1940s 3.98%
1950s 3.99%
1960s 3.50%
1970s 3.97%
1980s 8.02% (Only 1980-1983)
How did I do the math?
The Early Retirement Now website has a spreadsheet as part of their Safe Withdrawal Series that lets you calculate data like this.
I have taken that spreadsheet and over the last few years highly customized it and vastly expanded the data, so I can calculate almost any scenario pretty much instantly.![]()
Even the original spreadsheet there would give you pretty close to what you want, if you want to run the numbers yourself.
I used the earlyretirementnow data for 'cash' pre 1934Alpha4 wrote: ↑Tue Sep 19, 2023 12:02 pmOne, what interest rate did you use for pre-1934? Commercial paper rates are too high before about 1922/1923 (or maybe even 1924) vs what would've been earned on an actual risk-free asset (can show proof of this if you want); before the early to mid-1920s commercial paper did carry at least some default risk/late payment risk and the rates on it reflected this to a degree. FWIW I have looked at the commercial paper rates used in the simba/Siamond bond returns simulator spreadsheet and they seem to overstate returns on what could've been achieved on a true risk free instrument (or at least the closest thing to it before Treasury Bills came along) by anywhere from maybe 55-60 basis points to 120 or 130 basis points (it varies by year).seajay wrote: ↑Tue Sep 19, 2023 10:06 amThanks for that https://earlyretirementnow.com/safe-wit ... te-series/ website and spreadsheet pointer. I was surprised to see it included gold monthly data as well. I wouldn't count gold as gold pre 1934 however, as money was gold/silver back then (gold standard) and many might have deposited that money (gold) in return for interest (more gold/silver). Adjusting to account for that (gold=cash interest pre 1934), and moving bond risk over to the stock side, 50/50 stock/gold
4% SWR was supported over nearly all 30 year periods since 1871 (monthly granularity).
Seen as a reserve for opportunistic purchases and gold had a historic tendency to move counter-cycle to stocks over multiple years. When stocks were down -25% so gold might have been up +33% and vice versa. If at such times you migrated gold into 'cheap' stocks at some point during the 30 years then you ended up with more shares being held than had you lumped into stocks alone at the start, and where around two-thirds of those shares were bought at a -25% discount. Both your risk of a early years bad sequence of returns risk was reduced, whilst the mid/longer term prospects were ... (very) good.
Two, if I were you I would just simulate using silver back to 1900 (and until 1973 or 1974) in lieu of gold for that 50% of the portfolio rather than assuming half of the portfolio was in interest-bearing instruments....no doubt this will reduce the SWR vs assuming that 50% of the portfolio was invested in interest paying cash but--unless gold/silver start paying interest magically for some reason since today they obviously do not--this will provide a fairer equivalent to what gold and silver are today. How much does doing this reduce the SWR for each starting year from 1900 to 1974?
You stated inflation adjusted withdrawals and ending with zero balance remaining, which is the same as SWR. For each start year x% of the initial portfolio value is drawn in the first year, and in subsequent years that amount is uplifted by inflation ... where zero remained at the end of (in your case) 40 years. So a inflation adjusted withdrawal rate.
I use Simba spreadsheet as the calculator, which indicates for 40 year 30/70 TSM/ITT (total stock market/intermediate term treasury's, worse historic case of all of the historic cases within the 1926 onward period you specified)Given the information below, does anyone know how to calculate the worst real return?
- 30% Equities (S&P 500)
- 70% Fixed income (10 yr Treasuries)
- Inflation-adjusted withdrawals (linear, and with zero ending balance)
- Looking within any 40 year span since 1926
This is my attempt to answer your question. You may want to double check my math and methodology since I haven’t done a calculation like this before but thought it might be educational to try. And it’s for a 35 year period, not the 40 years you asked for, but it’s the best I can do.
Doesn't real return and a zero ending balance imply SWR? If not it seems like a fine distinction.
Nice!southernlucky wrote: ↑Wed Sep 20, 2023 8:31 am Hi op. Play with the start and end dates with this online historical portfolio allocation returns calculator at www.wealthmeta.com to see nominal and real returns for various stock/bond AA. Doing a quick check at the start of each decade looks like 1940-1980 (~40 yrs) was 5.4% CAGR nominal and a low of 0.9% CAGR real for 30/70. There could be worse results found if doing it year-by-year.
https://www.wealthmeta.com/calculator/p ... enceLine=5
Thank you. Much appreciated.southernlucky wrote: ↑Wed Sep 20, 2023 8:31 am Hi op. Play with the start and end dates with this online historical portfolio allocation returns calculator at www.wealthmeta.com to see nominal and real returns for various stock/bond AA. Doing a quick check at the start of each decade looks like 1940-1980 (~40 yrs) was 5.4% CAGR nominal and a low of 0.9% CAGR real for 30/70. There could be worse results found if doing it year-by-year.
https://www.wealthmeta.com/calculator/p ... enceLine=5