Is your understanding of this only from that line or do you have a more deeper take on it.

Back in 1920s, govt could 'adjust' the gold standard by changing the rate whenever they wanted.

Wanna double the money supply by 60%? Change the gold standard peg from 1.505g to 0.888g of gold.

When you didn't do that, you got a very short lived depression of 1920-1921 [1].

When you did, like FDR did in 1933, you got a long, extended deperession.

1. https://en.wikipedia.org/wiki/Depression_of_1920%E2%80%93192...