Probability of a 'Depression'

Robert Barro in a Wall Street Journal editorial provides some evidence to formulate the probability of a mild "depression" as defined as real GDP decline of over 10%. Based on his data, he estimates the probability at around 20%. The probability of a major depression (real GDP decline more than 25%) at around 9%. The last statement he makes deserves repeating here:

I wish I could be confident that the array of U.S. policies already in place and those likely forthcoming will be helpful. But I think it more likely that the economy will eventually recover despite these policies, rather than because of them.

Unfortunately, I am afraid I agree with him. I hope we are wrong and our recovery is more rapid, but it increasingly seems the structural adjustments the economy is progressing through are deeper than anticipated.