Andy Harless comments on Japan and the liquidity trap:

These fancy-schmancy DSGE models just lead to confusion. I have a pretty good intuitive idea of what's happening in Japan. There is a hypothetical bad equilibrium -- essentially a speculative bubble with money as the bubble asset, although, since money is the unit of account, most people think of the bubble as a "loss of confidence" in everything except money -- but you never really get to the bad equilibrium (we kind of did in 1929-1933, until devaluation popped the bubble), because central banks (which either won't or can't do what's needed to pop the bubble) stir up the water as much as possible to avoid moving toward equilibrium, and also because nominal wages are sticky downward, which slows down the progress of the bubble, and also probably because, if the bubble were allowed to progress, people would eventually realize that it's silly to hoard an asset without intrinsic value. (The 1929-1933 contraction was essentially a bubble in monetary gold. I imagine that bubble would eventually have ended on its own, as people realized how ridiculous the value of gold was getting relative to everything else, but it might have taken a whole lot of deflation to get to that point.) The ability to capture my intuition in an DSGE model is limited, because we're always far away from the actual bad equilibrium. Maybe a DSGD model, but that's even more confusing.