Branko Milanovic over at his website, Global Inequality:
Economists are often in particular demand because they claim they can tell the shape of future demand and supply, unemployment and growth. To do that they resort to models that through behavioral equations and identities, show the future evolution of key variables and pretend to predict how long the depression will last and how quick and strong the recovery will be.
My argument is that such models are useless under today’s conditions. There are several reasons for that.
All economic models, by definition, take the economy as a self-contained system which is exposed to economic shocks, whether in form of more or less relaxed monetary policy, higher or lower taxes, higher or lower minimum wage etc. They cannot by their very nature take into account extra-economic discrete shocks. Such shocks are simply not predictable. One cannot tell today whether China might invade Hong Kong, or whether Trump might ban all imports from China, or whether the race riots in the US can continue for months, or similar riots break out elsewhere in the world (Latin America, Africa, Indonesia) or even if the US may not end this year with a military government in charge.
All of these social and political shocks that I have listed are due to, or have been exacerbated, by the pandemic. There is little doubt that the “most important relationship” (to quote Henry Kissinger), the one between China and the United States, has significantly deteriorated because of the pandemic. Some in the United States see the pandemic as intentionally engineered by China to weaken the US economy and its president.
More here.