Eight times a year, a committee meets in Washington and the world's markets hold their breath. The FOMC doesn't set your mortgage rate, your car-loan rate, or your credit-card rate — yet within days of its announcement, all of them move. That's monetary policy: the Fed steering one overnight interest rate and letting arbitrage carry the impulse through every borrowing decision in the economy. This lesson gives you the graph where that steering happens (the money market), the toolbox (old-style and modern), and the chain of dominoes the AP loves to make you narrate: tools → rate → investment → AD → GDP and prices. Learn the chain cold; it's the most-asked sequence in Unit 4.
The money market determines the nominal interest rate in the short run.
Equilibrium: MD crosses MS at the nominal rate. MS right → rate falls; MS left → rate rises; MD right (with MS fixed) → rate rises.
| Tool | Expansionary (fight recession) | Contractionary (fight inflation) |
|---|---|---|
| Open market operations (the workhorse) | Buy bonds → reserves ↑ → MS ↑ | Sell bonds → reserves ↓ → MS ↓ |
| Discount rate (Fed's loan rate to banks) | Lower | Raise |
| Reserve requirement | Lower (rarely used) | Raise (rarely used) |
Memory hook: buy = bigger money supply; sell = smaller. OMOs work through Lesson 9's multiplier: reserves injected multiply into deposits.
The federal funds rate — banks' overnight interbank lending rate for reserves — is the Fed's target; the tools exist to move it.
Since banks now hold abundant reserves, small OMOs can't move the funds rate — the classic supply-demand squeeze doesn't bind. Instead the Fed steers with administered rates:
Exam translation: expansionary = lower IORB/administered rates (ample) or buy bonds (limited); contractionary = raise IORB or sell bonds. Know both vocabularies — the CED requires the ample-reserves framing, and older-style questions still use OMOs.
Expansionary: Fed buys bonds (or lowers IORB) → MS ↑ → nominal interest rate ↓ → investment and interest-sensitive consumption ↑ → AD shifts right → real GDP ↑, price level ↑, unemployment ↓.
Contractionary: sell bonds / raise IORB → MS ↓ → rate ↑ → I ↓ → AD left → output ↓ (toward Yf), PL ↓.
The real-interest-rate thread: in the short run with sticky inflation expectations, moving the nominal rate moves the real rate — and the real rate is what investment answers to. (Long-run: money can't move Yf; more money just means higher prices — Lessons 4 and 13's quantity-theory anchor.)
Monetary vs. fiscal, permanently distinguished: Fed/money/interest rates vs. Congress/G/taxes. A bond purchase by the Fed is monetary; a spending bill is fiscal. Both shift AD; the mechanisms differ — and the exam mixes them in the same question stem to catch skimmers.
Apply It: The economy has an inflationary gap. Name the OMO, the IORB move, and the chain. → Sell bonds / raise IORB → MS ↓ (or funds rate ↑ directly) → nominal rate ↑ → I ↓ → AD left → output falls to Yf, price level falls.
[GRAPH: The Money Market — expansionary policy
X-axis: Quantity of money
Y-axis: Nominal interest rate (i)
Curve 1: MD, downward-sloping
Curve 2: MS₁, vertical at Q₁
Equilibrium at (Q₁, i₁)
Shift: Fed buys bonds → MS shifts right to MS₂ (vertical at Q₂) →
new equilibrium (Q₂, i₂ < i₁) → nominal rate falls]
[GRAPH: Companion AD-AS — the transmission's destination
X-axis: Real GDP; Y-axis: Price level
Curves: LRAS at Yf; SRAS; AD₁ crossing SRAS left of LRAS (recessionary gap)
Shift: lower interest rate raises I → AD₁ → AD₂ rightward →
new equilibrium at (Yf, PL₂ > PL₁)]
AP labeling requirements: money market's y-axis is the nominal interest rate (write "nominal" — the loanable funds graph next lesson uses real, and mislabeling costs the point); MS must be vertical and labeled; show the shift with arrow and both equilibrium rates dashed. FRQs typically demand the pair: money market graph + AD-AS graph, connected by one sentence about investment.
1. E. The Fed chooses the money stock; the rate doesn't feed back into the chosen quantity — hence vertical. A: demand's shape is separate. B: velocity belongs to the quantity theory. C: banks influence deposits, but the Fed controls the base. D: no such mechanism in the model.
Fix: Vertical MS = policy-chosen quantity; only the Fed moves it.
2. B. Holding money means forgoing interest; the higher the rate, the costlier the convenience — quantity of money demanded falls. A: rates emerge from the market here. C: rate ≠ inflation. D: that's the real rate's home. E: plainly false.
Fix: MD slopes down because the nominal rate is money's price tag.
3. D. Recession → expand: buy bonds, injecting reserves. A/B/C: all contractionary. E: that's fiscal policy — wrong institution.
Fix: Recession = buy bonds / cut rates; check the institution before the tool.
4. A. Purchases add reserves → MS (vertical) shifts right → rate falls along MD. B/D: demand didn't move. C: MS stays vertical wherever it stands. E: the reserve injection is immediate.
Fix: OMOs move the vertical MS line; read the new rate off MD.
5. C. With abundant reserves, the funds rate follows the administered floor: raise IORB → banks demand at least that to lend → funds rate rises. A: small OMOs can't bite when reserves are ample. B: blunt and effectively unused (requirement ≈ 0). D: lowering the discount rate eases, not tightens. E: the Fed doesn't command loan volumes.
Fix: Ample reserves = administered rates rule; IORB is the floor that drags the funds rate.
6. D. The four-link chain: money up, rate down, investment up, AD right — output rises. A: that's contraction. B/E: fiscal chains. C: rate direction wrong and saving isn't the vehicle.
Fix: Narrate every link: MS → i → I → AD → Y/PL. Skipped links = lost points.
7. B. Higher prices mean more dollars needed per transaction → MD right → rate rises given fixed MS. A/D: supply is policy-set. C: direction reversed. E: the price level shifts MD (it's not on this graph's axes).
Fix: MD shifts with the price level and real GDP; the interest rate moves you along it.
8. E. Banks pay for the bonds with reserves → reserves fall → lending and deposits contract by the multiplier logic. A: backwards. B: expansion is the buy-side result. C: required reserves fall only as deposits shrink — the cause is the reserve drain. D: opposite.
Fix: Sell = drain reserves = shrink money; the multiplier runs in reverse too.
9. A. Definition: interbank overnight reserves rate, the Fed's operating target. B: discount rate. C/D/E: unrelated rates.
Fix: Fed funds = bank-to-bank overnight; discount = Fed-to-bank; don't swap them.
10. C. Tighter money → higher rates → less I → AD left: output and price level both fall. A: SRAS isn't the policy channel. B: expansionary description. D: money never moves LRAS. E: something must shift for equilibrium to move.
Fix: Monetary policy is an AD story — pick the direction, shift AD, read both effects.
11. B. IORB is a risk-free floor: no bank lends below it, so raising it lifts the whole overnight market. A: lowering IORB is expansionary. C: it's paid to banks on reserves, not to consumers. D: it works on the supply/pricing of reserves, not money demand. E: the Fed sets it.
Fix: IORB up = rates up = tightening; the floor drags the market.
12. E. From Yf, monetary stimulus pushes AD right: output temporarily above potential, prices up — an inflationary gap that wage adjustment will later unwind. A: money is neutral in the long run only. B/C/D: wrong directions.
Fix: Stimulus at full employment buys a temporary boom and a permanent price increase.
13. D. Inflationary gap → tighten: sell bonds, raise IORB/administered rates. A/B/C: tools point the wrong way for the stated gap. E: stimulating at full employment ignites inflation.
Fix: Diagnose the gap first; the toolbox direction follows automatically.
The economy of Trevana is in a recessionary gap. Trevana's central bank operates under a limited-reserves framework with a reserve requirement of 10%.
(a) Draw a correctly labeled graph of the money market in Trevana, showing the initial equilibrium nominal interest rate i₁.
(b) Identify the open-market operation the central bank should use to address the recessionary gap.
(c) Show the effect of this operation on your money market graph, labeling the new interest rate i₂.
(d) The central bank purchases $20 million of bonds from commercial banks. Calculate the maximum possible change in the money supply. Show your work.
(e) Explain how the change in the nominal interest rate affects aggregate demand. Identify the specific component of AD involved.
(f) Draw a correctly labeled AD–SRAS–LRAS graph showing the effect of the policy on Trevana's real output and price level. (Assume the policy exactly closes the gap.)
(g) In the long run, if the central bank had instead done nothing, how would Trevana have returned to full employment? State the mechanism.
1. E. The Fed chooses the money stock; the rate doesn't feed back into the chosen quantity — hence vertical. A: demand's shape is separate. B: velocity belongs to the quantity theory. C: banks influence deposits, but the Fed controls the base. D: no such mechanism in the model. Fix: Vertical MS = policy-chosen quantity; only the Fed moves it.
2. B. Holding money means forgoing interest; the higher the rate, the costlier the convenience — quantity of money demanded falls. A: rates emerge from the market here. C: rate ≠ inflation. D: that's the real rate's home. E: plainly false. Fix: MD slopes down because the nominal rate is money's price tag.
3. D. Recession → expand: buy bonds, injecting reserves. A/B/C: all contractionary. E: that's fiscal policy — wrong institution. Fix: Recession = buy bonds / cut rates; check the institution before the tool.
4. A. Purchases add reserves → MS (vertical) shifts right → rate falls along MD. B/D: demand didn't move. C: MS stays vertical wherever it stands. E: the reserve injection is immediate. Fix: OMOs move the vertical MS line; read the new rate off MD.
5. C. With abundant reserves, the funds rate follows the administered floor: raise IORB → banks demand at least that to lend → funds rate rises. A: small OMOs can't bite when reserves are ample. B: blunt and effectively unused (requirement ≈ 0). D: lowering the discount rate eases, not tightens. E: the Fed doesn't command loan volumes. Fix: Ample reserves = administered rates rule; IORB is the floor that drags the funds rate.
6. D. The four-link chain: money up, rate down, investment up, AD right — output rises. A: that's contraction. B/E: fiscal chains. C: rate direction wrong and saving isn't the vehicle. Fix: Narrate every link: MS → i → I → AD → Y/PL. Skipped links = lost points.
7. B. Higher prices mean more dollars needed per transaction → MD right → rate rises given fixed MS. A/D: supply is policy-set. C: direction reversed. E: the price level shifts MD (it's not on this graph's axes). Fix: MD shifts with the price level and real GDP; the interest rate moves you along it.
8. E. Banks pay for the bonds with reserves → reserves fall → lending and deposits contract by the multiplier logic. A: backwards. B: expansion is the buy-side result. C: required reserves fall only as deposits shrink — the cause is the reserve drain. D: opposite. Fix: Sell = drain reserves = shrink money; the multiplier runs in reverse too.
9. A. Definition: interbank overnight reserves rate, the Fed's operating target. B: discount rate. C/D/E: unrelated rates. Fix: Fed funds = bank-to-bank overnight; discount = Fed-to-bank; don't swap them.
10. C. Tighter money → higher rates → less I → AD left: output and price level both fall. A: SRAS isn't the policy channel. B: expansionary description. D: money never moves LRAS. E: something must shift for equilibrium to move. Fix: Monetary policy is an AD story — pick the direction, shift AD, read both effects.
11. B. IORB is a risk-free floor: no bank lends below it, so raising it lifts the whole overnight market. A: lowering IORB is expansionary. C: it's paid to banks on reserves, not to consumers. D: it works on the supply/pricing of reserves, not money demand. E: the Fed sets it. Fix: IORB up = rates up = tightening; the floor drags the market.
12. E. From Yf, monetary stimulus pushes AD right: output temporarily above potential, prices up — an inflationary gap that wage adjustment will later unwind. A: money is neutral in the long run only. B/C/D: wrong directions. Fix: Stimulus at full employment buys a temporary boom and a permanent price increase.
13. D. Inflationary gap → tighten: sell bonds, raise IORB/administered rates. A/B/C: tools point the wrong way for the stated gap. E: stimulating at full employment ignites inflation. Fix: Diagnose the gap first; the toolbox direction follows automatically.
Exam tip: Monetary FRQs are graded link by link: money market graph (nominal axis!), the OMO or IORB move, the rate change, the component of AD (investment — name it), the AD shift, and both final effects (output AND price level). Write the chain as arrows before drawing anything, then illustrate. Next lesson: the money market's cousin with the real interest rate on the axis — loanable funds — and the crowding-out story fiscal policy left hanging.