The Watchtower and it's apologists really need to pick up a history book now and then. There have been world events which made the events after 1914 appear as insignificant. I do not have the figures in front of me, but the "Black Death" that swept through Europe had catostrophic consequences in terms of loss of life (killing approx. one half of the European population, I believe). It also had incredibly damaging consequences to trade and commerce as well.
Even if there were a major market collapse, the consequences would not be nearly as dire as were prevalent in the 1930s. Part of the economic woes were due to the lack of the social safety net implemented later on (Social Security, Medicare, unemployment benefits, etc.) The 1930s also saw the collapse of U.S. agriculture with the "Dust Bowl" that swept through the midwest.
As regards to the JW's recent apocalyptic anticipations, I think there is something truly pathalogical about a movement who wishes to see mass disaster and human suffering so that their exclusive group can be ushered into their promised utopia. I find it to be borderline sociopathic, in fact.