FINS3616 · International Business Finance
The International Monetary System
Week 5 of UNSW FINS3616 surveys the international monetary system and exchange-rate regimes from fixed to floating (Shapiro Ch 3). It teaches the impossible trinity — a country can hold at most two of {fixed exchange rate, free capital mobility, independent monetary policy} — and connects regime choice to currency-crisis vulnerability. This is the institutional backdrop for the exposure, financing and country-risk chapters, and Week 5 carries increased weight on the 40% final exam.
What this chapter covers
- 01Exchange-rate regimes: free float, managed (dirty) float, target zone/band, crawling peg, fixed peg, currency board, dollarization / monetary union
- 02The impossible trinity (trilemma): at most two of {fixed exchange rate, free capital mobility, independent monetary policy}, and its corner solutions
- 03History: the classical gold standard (price-specie-flow adjustment), Bretton Woods (USD pegged to gold, IMF/World Bank), the 1971–73 collapse to a managed float, the EMS → the euro
- 04Balance of payments: current account + capital/financial account ≈ 0; a current-account deficit financed by net capital inflows
- 05Official reserves and central-bank intervention supporting a peg; how reserve depletion breaks a peg
- 06Optimum currency area criteria (labour mobility, fiscal transfers, business-cycle synchronisation) and the euro's costs/benefits
- 07Regime choice and currency-crisis vulnerability — how a fixed peg with free capital flows becomes fragile
- 08Links forward to transaction/economic exposure and country risk
Applying the impossible trinity to a peg under pressure
- +1State the trilemma: a country can maintain at most two of the three — a fixed exchange rate, free capital mobility, and an independent monetary policy. It must give up the third.
- +1Identify Country X's choices: it has committed to a fixed peg AND free capital mobility. Those are its two, so the leg it necessarily sacrifices is an independent monetary policy.
- +1Explain the constraint: cutting domestic rates below foreign rates would trigger capital outflows (investors chase higher yields abroad). They sell the currency, forcing the central bank to defend the peg by buying its own currency with reserves — draining reserves until the peg is unsustainable. So it cannot run an independent easing policy while keeping the peg and open capital account.
- +1Set out the three corners: (i) keep the peg + free capital but import the anchor country's monetary policy (no independence); (ii) keep the peg + independent policy but impose capital controls; (iii) float the currency to regain independent policy alongside free capital flows.
Key terms
- Impossible trinity (trilemma)
- A country can maintain at most two of three policies at once: a fixed exchange rate, free capital mobility, and an independent monetary policy. Choosing any two forces it to give up the third — the organising idea of regime choice.
- Currency board
- A monetary regime with essentially no central-bank discretion: the local currency is fully backed by, and pegged to, an anchor currency. It delivers a hard peg at the cost of an independent monetary policy.
- Dollarization
- Complete replacement of the local currency with the US dollar (currency substitution). It can deliver price stability but the country loses seigniorage and all monetary autonomy.
- Gold standard / Bretton Woods
- The classical gold standard (pre-1914) fixed currencies to gold with automatic price-specie-flow adjustment; Bretton Woods (1944–1971) pegged the USD to gold and other currencies to the USD, and created the IMF and World Bank before collapsing in 1971–73.
- Balance of payments
- The record of a country's external transactions: the current account (trade, income, transfers) plus the capital/financial account sum to approximately zero, so a current-account deficit is financed by net capital inflows.
- Optimum currency area
- The set of criteria — labour mobility, fiscal transfers, business-cycle synchronisation — under which a group of economies benefits from sharing a single currency. It frames the costs and benefits of the euro.
The International Monetary System FAQ
What is the impossible trinity and why does it matter?
It is the constraint that a country can hold at most two of three things at once: a fixed exchange rate, free capital mobility, and an independent monetary policy. It matters because it explains regime choice and crisis vulnerability: a country that fixes its rate and keeps its capital account open cannot also set interest rates freely, so a shock that calls for easing can force it to choose between abandoning the peg, closing the capital account, or importing the anchor country's policy. Most Week-5 monetary-system questions are really trilemma questions in disguise.
How does a fixed peg actually break?
Through reserves. To hold a peg the central bank must intervene — selling foreign reserves to buy its own currency when the currency is weak. If domestic policy or fundamentals are inconsistent with the peg (for example, easing while the capital account is open), capital flows out, the currency is sold, and the central bank burns reserves defending it. Once reserves are exhausted (or expected to be), the peg becomes unsustainable and is abandoned, often abruptly — a currency crisis. Free capital mobility makes this dynamic faster and larger.
Why did the gold standard and Bretton Woods matter, and why did they end?
The classical gold standard fixed currencies to gold with an automatic adjustment mechanism, and Bretton Woods rebuilt a fixed system after 1944 by pegging the US dollar to gold and other currencies to the dollar, creating the IMF and World Bank. Both eventually broke because a fixed system cannot absorb persistent imbalances and divergent national policies indefinitely — Bretton Woods collapsed in 1971–73 when the dollar's gold convertibility became untenable, giving way to today's managed float. The history is the institutional context for why exposure management matters.
Can AI help me with the international monetary system in FINS3616?
Yes, as a study aid. Sia is an AI tutor built to mirror how FINS3616 is taught and assessed at UNSW Sydney: it can quiz you on classifying regimes into the trilemma corners, walk through how a peg is defended and broken, and explain the balance-of-payments identity and optimum-currency-area criteria step by step. It checks your reasoning but does not do graded assessment, and UNSW academic-integrity rules apply — this Week-5 material carries extra weight on the 40% final, so use it to prepare.
Exam move
Make the impossible trinity your master tool for this chapter: for any regime a question describes, name the two legs the country has chosen and read off the third it must sacrifice — that single move answers most Week-5 monetary-system questions. Build a compact table of the regimes (free float → managed float → band → crawling peg → fixed peg → currency board → dollarization) ordered by how much monetary autonomy each surrenders, and be able to place real countries on it. Know the historical arc (gold standard → Bretton Woods → 1971–73 collapse → managed float → EMS → euro) well enough to explain why each system ended, and keep the balance-of-payments identity and optimum-currency-area criteria ready as short-answers. Because Week 5 is flagged for increased weight on the cumulative 40% final exam, rehearse these as concise written arguments rather than calculations. When a regime classification won't click, ask Sia to test you on fresh examples and mark your reasoning.
Working through The International Monetary System in FINS3616? Sia is AskSia’s AI Business and Economics tutor — ask any FINS3616 The International Monetary System question and get a clear, step-by-step explanation grounded in how FINS3616 is taught and assessed. Read this chapter free, then take your hardest questions to Sia.
