So, instead of increasing demand we decrease supply by having people work and thus produce less?
Simplifying that, we will gain more by producing less?
Simplifying that, we will gain more by producing less?
They're basically arguing that e.g. instead of 10 workers producing 10 widgets, you have 12 workers produce 10 widgets with each of them taking more vacation. Labour costs go up, some more wealth gets shifted back to labour, and this increases aggregate demand without changing supply.