Principles of Macroeconomics / Unit 12 MAC 1135 review, 2 to 3 minutes
Why Expansionary Monetary Policy Can Fail
The idea
Contractionary policy always bites, and expansionary policy may not, and the asymmetry is worth stating as the unit's most useful single lesson. Draining reserves forces lending down, because a bank short of required or desired reserves must act. Adding reserves only offers the chance to lend, and a bank may decline it. The old description is that contraction is pulling on a rope while expansion is pushing on a string: pull and the far end follows, push and the rope buckles. There are four distinct routes to failure and they can operate together. The first is lags, named at unit ten and worked at unit fourteen, with monetary policy's own impact lag running from about six months to two years, so a remedy can arrive after the problem has passed and push the economy the wrong way. The second is excess reserves: banks hold more of them in recessions, exactly when lending is wanted, and paying interest on reserves gives them a further reason to. The third is the zero lower bound, where the nominal rate cannot fall further and deflation raises the real rate anyway. The fourth is unstable velocity, so that a given increase in money need not raise spending at all.
In practice
Worked example, the four together. An economy falls into a deep recession. The central bank cuts its policy rate to near zero, so the first tool is exhausted. It buys bonds heavily and bank reserves rise, but firms are pessimistic about demand and do not want to borrow, while banks facing uncertain losses prefer to hold the reserves. Lending barely moves, so the money supply barely moves. Households expecting further price falls delay purchases, so velocity falls, and nominal spending stays flat even though the money base has grown. Prices drift down, which raises the real interest rate while the nominal rate sits at zero. Every link in the chain from unit 1126 is intact and each one is transmitting almost nothing.
Where people slip
Three cautions. First, this argument is about what monetary policy alone can do, and it is a standard reason given for combining it with fiscal policy, which is unit fourteen's subject rather than a verdict here. Second, central banks responded to exactly this situation with quantitative easing and by extending credit to a wider range of institutions, and the evidence on how well those worked is genuinely mixed: the anchor rates the first round above the later ones, and researchers disagree about the one long episode most often cited. Third, none of this shows expansionary policy never works. It shows that its effect depends on conditions the central bank does not control, which is a different and more useful claim.
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