And maybe the best economic copy I’ve read this week:
This assumption that people behaved in reliable, predictable ways was often equivalent to assuming that people in the economy were stupid and could be repeatedly fooled. If you wanted to spur the economy, just apply a burst of stimulus spending or pump up the money supply. When the economic agents in the economy—say, gullible store owners—saw customers coming through the door, flush with the new cash, they would conclude that happy days were here again and ask their suppliers to ramp up production; the economy would then spring to life. Those store owners wouldn’t stop to ask whether the stimulus would be paid for by higher future taxes, or whether the newly printed money would cause inflation, thereby undercutting its value. They would just suffer the rude surprises later on.
In rational expectations models, the people are smarter; they know what’s going on. If you offer them goodies today, paid for by taxes tomorrow, they look at both sides of the ledger, not just one. To the dismay of graduate students, this makes the math much harder. It also undercuts some of the old verities. At a dinner with Sims, when I was just coming out of graduate school, I made some mention of aggregate demand. He asserted that there was no such thing. This was deeply unsettling, even after my exposure to teachers like Sargent and John Taylor. More importantly, the rational expectations approach implies that the challenges are much greater for the economic policy maker, who now needs to worry about savvy economic counterparties who understand the game.
Why should we set aside our old, nice, simple economic models in favor of ornate new ones? Only because the old ones were not working very well.
Read the whole golshderned thing.
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