Physicists and mathematicians have puzzled over the three-body problem – the question of how three objects orbit one another according to Newton’s laws. No single equation can predict how three bodies will move in relation to one another and whether their orbits will repeat or devolve into chaos.
John Mauldin of Mauldin Economics wrote about the eight-body problem in economics in which we cannot predict how the economy will react when eight variables change. He lists the following:
What is certain is that as government fiscal intervention starts to lose its effectiveness it will be inevitable that monetary policy will continue to remain very accommodating with bond buybacks and record low interest rates. COVID-19 has turned conventional economic thinking upside down.