What do we โknowโ about investing โ but canโt prove with stats?
That psychology, sociology and and assiduously studying what people are thinking is just as important as any quant pseudo-math, if not more so.
Economics is really just psychology and sociology translated into monetary terms, and pecuniary issues just cannot be abstracted into the realm of pure math. Itโs just more physics envy which is detrimental to many fields, economics included. While statistical techniques are useful, they are merely a start. The most important aspects of investment just cannot (and maybe can never be) captured statistically. Most of the time itโs just useful as a post hoc analysis.
In many ways, weโve probably reached or are near the limits of what stats in quite a few fields can get us โ at least without beyond-human level intellects.