It's totally misleading to think of the economy as a pond holding a fixed quantity of water. The water level does change, and sometimes you need to make waves to do it.
At any given moment, the available resources ARE fixed. They aren't increased by moving them around.
If you increase the amount of money available, that bids up prices for the existing resources.
If low skilled labor is already fixed at an artificially high price (like a minimum wage), a general price increase will reduce the value of the fixed wages paid under these arrangements and increase employment.
But you could accomplish the same thing by lowering the minimum wage.
No additional value is created by stimulus. The extra money is just undermining the effect of things that have been hobbling the market all along.
But creating more money has other destructive effects and causes people to make unsound investments. It creates bubbles. These bad results can take years to develop.
All the quantitive easing the Federal Reserve did after the financial crisis has helped re-inflate the housing bubble. Rising rents that also cause people to have to move or suckers them into buying into the bubble. A replay of earlier stimulus.
While all the churn in the economy benefits some industries, it destroys wealth for all income levels in the long run. It puts the country in further debt and makes us weaker.
Instead of resources flowing to industries that make the country more prosperous in the long run, we over-invest in real estate.
Without all the subsidies, both direct and indirect, real estate would be a much smaller part of the economy and there would be more capital for investments that actually create more wealth, instead of things that merely appear to do so in the short run.
The babysitting co-op Krugman referred to was a barter market where people can only trade ONE thing.
And where each member had to contribute 14 hours worth of babysitting a year just to pay for using the system. That's why there was more supply than demand in that "market" when it started.
For this, you should read Paul Krugman's babysitting co-op analogy, a basic description of how an economic depression functions: https://en.wikipedia.org/wiki/Capitol_Hill_Babysitting_Co-op