What was the economic result of demobilization in 1920 America on farm boys who had seen the world and big cities?
One of the intriguing effects of both the return from soldiers who had seen Europe as well as the general beginning of mechanization on the farm from the 1920's continuing even to the present is the change in the necessity of human labor on the farm and the change as well in the profitability and sustainability of farming models.
Of course there were the psychological effects of boys who had seen Europe and may have wanted a more cosmopolitan life than was available down home on the farm, but the economic effects of the changing world on the farm were far more far-reaching and devestating depending on your outlook.
As tractors and other mechanical aids became more and more common after the war (and cheaper thanks to some of the surplus tank treads and research that went into those machines) more and more farmers began to mechanize which led to consolidation and a drive towards crop yield as the main measure of success as opposed to perhaps quality or consistency. The long-reaching effect is the transition to the factory farm and the migration of a great deal of labor from the farm fields to the cities.