For what it is worth, here is the heart of Shiller's suggestion from an article in The New Republic:
We first have to come to grips with the fact that we need stimulus because we’re facing a problem of inadequate aggregate demand, a concept that we owe to the work of John Maynard Keynes. Keynes pointed out that a national economy can get stuck in a bad equilibrium—as it had in the Great Depression in 1930—where unemployed people really wish to supply their labor to some employer, but employers won’t hire them because they don’t think that the extra product they would make could be sold. Why not? Because of all the unemployed people trying unsuccessfully to supply their labor who can’t afford to buy anything. And why aren’t they working? Because no one will hire them.A generation from now the American public will look back over the period from 1980 to 2020 as a disaster in public policy, a scorched earth fought over by (mostly Republican) fanatics without regard for the public interest. A battlefield of fanatical ideas by partisans deaf, dumb, and blind to reason and compromise.
That sounds circular, but that was exactly Keynes’ point. The whole depression situation is just an absurd circularity that we get stuck in from time to time, and can stay stuck in for a very long time. The core idea of Keynes’ theory is that there’s no fundamental reason to be in such a weak economy except the fact that we’re in it.
The problem is essentially one of communication: Somehow the unemployed have to communicate—not just in words but in the marketplace—their desire both to supply their labor and also to buy the excess of goods they would produce with the income from that labor. Part of Keynes’ idea, not always explained in the subsequent discussions of the theory, is that what has to be communicated is not any objective facts or information, but an intuition—a sense of confidence, a sense that the worst is over, a sense that the people’s animal spirits are back. If we think confidence is returning, then confidence will return.
The medium through which that communication largely needs to occur is collective action. We need to assert as a nation our will to get out of the bad equilibrium and get moving. And the way to do that is through government stimulus: We need to increase government expenditure for as long as it takes to break out of our rut. And there’s no use denying that those government expenditures will need to increase substantially in order to reduce the unemployment rate measurably.
That brings us to a critical fallacy that has crept into our thinking: We have become habituated to the idea that Keynesian fiscal stimulus has to take the form of deficit spending. After a credit downgrade by S&P, there’s a strong argument to make that the U.S. government is in no position to make a massive further increase in the national debt—but that's not an argument against stimulus as such. The fallacy is to think that stimulus necessarily needs to run up the national debt.
In reality, stimulus can easily take a balanced budget form: The government can simply raise taxes and raise expenditures by the same amount. The idea that balanced budget increases could save an economy stuck in a bad equilibrium goes back to the work of economists Walter Salant and Paul Samuelson in the 1940s, and it’s been taught in introductory economics courses ever since, though somehow it has been absent from public discussion of the current economic situation. Salant and Samuelson argued that in a very weak economy the balanced budget expenditure increases would translate into a one-for-one increase in national income.
In fact, the returns on a balanced budget stimulus are likely to be even greater than that. If the government raises taxes to hire the unemployed, then the unemployed who now get jobs will likely quickly spend all the money they earn on new consumption, since they have been strapped and now have jobs. The currently employed, who will see their taxes go up, will likely not cut their expenditures as much because they are habituated to their current level of consumption. And it is unlikely that a balanced budget stimulus would “crowd out” private expenditures on goods and services by pushing up interest rates. The Fed has already committed itself to keeping interest rates at zero until 2013.
The big problem with balanced budget stimulus is political, namely that there is a huge opposition to tax increases right now, primarily among Republicans.