The DJIA price time series prediction shows very strong cyclical pressure to the downside. Nevertheless, the divergence of the actual price to the predicted price is now at a historically high level going back to 1896. Since the current rate of QE(n+1) is $85 billion a month, which is without historical parallel, this price prediction may not stand the test of a few months. One conjecture I have is that were QE to end tomorrow, I suspect the price prediction would be much more accurate. I have tried to incorporate Fed POMO operations in the model, and they are worthless for the cyclical model I am using here in terms of increasing accuracy.
Added on 2013.08.14
So perhaps in the very short run, 2009 - 2013, POMO has indeed altered the length of the business cycles .