Number of years in results

[n5lfy123]

Number of years in results - Possible BUG?

I hope someone can help me understand the numbers in this statement in the results: "FIRECalc looked at the X possible Y year periods in the available data".

If I select a mixed portfolio, it says "based on performance since 1927". Up at the top of the page, it says "Data updated on May 8, 2022 thru 1/1/2022". Therefore, I assume there are 95 years of data (2022 minus 1927) for a mixed portfolio.

If I ask for the results of a 1 year investment with a mixed portfolio, I get the following: FIRECalc looked at the 78 possible 1 year periods in the available data.

Why is it 78 possible 1 year periods and not 95?

Thanks in advance for anyone who can help me to understand this.

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Added after the original post:

So I used the "provide data and formulas in a spreadsheet format, using 1927 as the starting retirement year in the spreadsheet showing a full retirement cycle (must be on or after the first year data were available, and early enough to show a full cycle)".

In the resulting spreadsheet it only generates results from 1927 through 2004.

Does anyone know why it doesn't generate results all the way through the full data set?

Is this a bug?

 

[Gumby]

Couldn't tell you, but I find it odd to run a retirement scenario lasting just one year. If all you are trying to do is find the average one year return of a mixed portfolio, I'm sure there are far better tools than FIRECalc.

 

[n5lfy123]

I'm not trying to model one year. I was using it to test the output and I don't understand the results.

 

[Gumby]

I'm not trying to model one year. I was using it to test the output and I don't understand the results.

It would appear that when the "mixed portfolio" option is selected, the program thinks it has only 78 years of data. I tested by varying the number of years on the first tab, and they are all consistent with a 78 year period of data (i.e. - if you pick 4 years, there are 75 runs, if you pick 14 years, there are 65 runs). By contrast, when selecting "Total Market" as a portfolio, it shows 151 years of data, which is consistent with data from 1871 to date.

That suggests to me that the performance data needed for the mixed portfolio calculation has either not been updated since about 2005, or is updated in some way I do not understand. For example, it could be that the data set is fixed at a 78 year period and contains only the last 78 years of data, regardless of what the verbiage says. I just don't know. And since I've never used that choice, I've never seen the problem.

 

[n5lfy123]

I think this is a bug. How can I report the possible bug to the author of FIRECalc? On the FIRECalc webpage it refers to this forum for bug reports.

 

[Gumby]

FIRECalc was created and is updated by dory36, who also started this board. You could send him a private message about the issue (look to the upper right of the page for the link to send a private message).

 

[n5lfy123]

send him a private message

Thank you. Done.