Must-Read: Olivier Blanchard: How to Teach Intermediate Macroeconomics after the Crisis?
Must-Read: Am I allowed to say that nearly all of this is in Paul Krugman’s 1998 The Return of Depression Economics?
: How to Teach Intermediate Macroeconomics after the Crisis?: “The IS relation remains the key to understanding short-run movements in output…
…In the short run, the demand for goods determines the level of output. A desire by people to save more leads to a decrease in demand and, in turn, a decrease in output. Except in exceptional circumstances, the same is true of fiscal consolidation. I was struck by how many times during the crisis I had to explain the ‘paradox of saving’ and fight the Hoover-German line, ‘Reduce your budget deficit, keep your house in order, and don’t worry, the economy will be in good shape.’ Anybody who argues along these lines must explain how it is consistent with the IS relation. The demand for goods, in turn, depends on the rate at which people and firms can borrow (not the policy rate set by the central bank, more on this below) and on expectations… animal spirits… largely self-fulfilling. Worries about future prospects feed back to decisions today….
The LM relation… is the relic of a time when central banks focused on the money supply…. The LM equation must be replaced, quite simply, by the choice of the policy rate by the central bank, subject to the zero lower bound. How the central bank achieves it… can stay in the background…. Traditionally, the financial system was given short shrift in undergraduate macro texts. The same interest rate appeared in the IS and LM equations…. This is not the case and that things go very wrong. The teaching solution, in my view, is to… discuss how the financial system determines the spread between the two….
Turning to the supply side, the contraption known as the aggregate demand–aggregate supply model should be eliminated…. One simply uses a Phillips Curve…. Output above potential, or unemployment below the natural rate, puts upward pressure on inflation. The nature of the pressure depends on the formation of expectations…. If people expect inflation to be the same as in the recent past, pressure takes the form of an increase in the inflation rate. If people expect inflation to be roughly constant… pressure takes the form of higher—rather than increasing—inflation. What happens to the economy, whether it returns to its historical trend, then depends on how the central bank adjusts the policy rate in response to this inflation pressure…. This… is already standard in more advanced presentations and the new Keynesian model (although the Calvo specification used in that model, as elegant as it is, is arbitrarily constraining and does not do justice to the facts). It is time to integrate it into the undergraduate model…. These modified IS, LM, and PC relations can do a good job….
I consider two extensions… expectations… openness. Here, also, there are important lessons from the crisis…. The long interest rate… as the average of future expected short rates, with a fixed term premium. Quantitative easing… can affect this premium…. Deriv[ing]… exchange rates from the uncovered interest rate parity condition… assumes infinitely elastic capital flows. The crisis has shown… capital flows have finite elasticity and are subject to large shocks beyond movements in domestic and foreign interest rates. Periods of ‘risk on-risk off’ and large movements in capital flows have been an essential characteristic of the crisis and its aftermath…