This is the proof you went away for months to seek?
They try to prove economics by comparing the Wizard of Oz book to the movie.
Well I can do that sort of thing:
There is no depression because in the book Harry Potter and the Prisoner of Azkaban, he received a Firebolt magic broom from an unknown source about halfway through said book (later revealed to be given by Sirius Black). While in the movie he didn't get his Firebolt until the very end of the movie. This shows that our economy is getting better, but it is a slow process as Hollywood shows by bumping back when Harry gets his firebolt. The message is clearly "the reward takes time but it will come."