Let me let you in on a little secret: most economists don’t know what they are saying.
Putting it more kindly, economists are far from certain about the explanations and predictions they put forward. For example, economists long warned about the dangers of high minimum wages. According to the standard textbook, high minimum wages worsen employment because they discourage firms from hiring. Likewise, most economists would once have seen the quantitative easing techniques rich-world central banks have used to expand their money supply as a sign of economic Armageddon.
In both instances, the textbook was wrong. Higher minimum wages do not routinely cause more unemployment, and quantitative easing has not led to rampant inflation in the developed world.
Don’t blame economists, though; they get things wrong so often because they rarely get the chance to test their theories