Can you count on backtested results?

In the coming weeks we will be posting the updated history of equity and fixed income returns for the last  53 and 95 years.  These returns will be used to study the impact of investing in combinations of equity asset classes as well as assuming they are being used in the accumulation and distribution periods of an investor's life. 

We must ask the question:  How meaningful are these historical returns?  Ben Carlson, one of our Truth Tellers, has written several articles on the topic.

https://awealthofcommonsense.com/2023/03/backtests-are-unemotional-humans-are-not/

https://awealthofcommonsense.com/2017/01/10-things-you-cant-learn-from-a-backtest/