Major “events” in markets have been caused by wrong assumptions over mathematical relationships. The Long Term Capital Management Debacle (LTCMD) in 1998 was primarily the result of the incorrect assumption of perfect markets by a cluster of Nobel Laureates. The naïve and wrong assumptions over correlations proved to be the spectacular undoing of the mortgage markets in 2007-8.
Currently, the US economy is stuttering. Headline growth during the latter half of 2023 was extremely rapid – GDP growth averaged more than twice the economy’s 20-year average - but this strong activity was led by the public sector, either directly through government investment or indirectly via the authorities’ support for household incomes.