The depression was caused by many situations. the rich getting richer, we where out producing more then what was demand, so on and so on. History will repeat itself. It is inevitable. America is at a point that F&^( up. CEOs make more than what they are worth. Sending jobs to third world country for cheap labor. Unions forced companies to paid more to there employee, health insurance, ect. I hate to say it, but will are one the way to a collaps country where we may see another civil war.
I would think that the main problem with CEO's isn't so much that they are paid more than they are worth, but
how they are paid-many a time, with stock options' that lead up to them having a considerable stake in a company; That can influence their decision to go with, say, a merger, wherein they might personally profit, but the same merger might result in the loss of Hundreds, or thousands or tens of thousands of other jobs...Or get's the purchasing company one step closer to having an overwhelming share of the market, making it hard for competitors.
I don't really think that unions have that big an impact anymore, though. Maybe back in the '70's, when Union labor of all trades and crafts made up a total of roughly 22% of the U.S. workforce. Today, It's less than 8%, I believe. Too small a group to really have much impact, anymore.
And, if we didn't have a Civil War in the 1930's, during the great depression, I really doubt we'll have one today. You might have some riots, but no outright armed conflict.