External stability in Australia: the CAD, net foreign liabilities, terms of trade and the exchange rate (HSC Economics Topic 3)
“Examine the economic issue of external stability including the measurement of the current account deficit (CAD), net foreign liabilities, the terms of trade and the exchange rate, and the causes and consequences of external instability for Australia”
External stability means avoiding excessive swings in Australia's external accounts and currency. The four indicators are the CAD (percent of GDP), net foreign liabilities (around 50 percent of GDP in 2024), the terms of trade, and the exchange rate. A falling terms of trade or rising net foreign liabilities can worsen external instability; a floating exchange rate acts as an automatic stabiliser.
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What this dot point is asking
NESA wants you to measure and explain external stability: the current account deficit (CAD) and its components, net foreign liabilities (debt plus equity), the terms of trade, and the exchange rate, and to analyse the causes and consequences of external instability for Australia. Expect a 5 to 8 mark short answer or stimulus question using ABS Balance of Payments data, or an extended response assessing how serious the CAD is.
Think of Australia as a household that regularly spends a bit more overseas (on imported cars, technology and holidays) than it earns from selling things overseas (mostly minerals like iron ore and coal). That gap is the current account deficit (CAD) - like a household running a small overdraft every month. To cover it, Australia borrows money from foreigners or lets them buy a share of Australian businesses and property, and the running total of everything owed, minus everything owned overseas, is net foreign liabilities (NFL) - like the household's total credit card and mortgage balance. The terms of trade is simply how good a "deal" Australia gets when it trades: if the price of iron ore shoots up while the price of the imported phone stays the same, Australia can sell less iron ore for the same phone, which is a favourable terms of trade, similar to getting a pay rise without your bills going up. Finally, the exchange rate is the "price tag" on the Australian dollar itself, and because Australia lets this price float freely, it acts like a pressure-release valve: if the overdraft (CAD) gets too big, the dollar tends to fall, making Australian exports cheaper and imports pricier, which naturally narrows the gap again - without a bank manager (the government) needing to step in.
The answer
Measuring external stability: the current account deficit
External stability refers to avoiding excessive fluctuations in Australia's external accounts and exchange rate, so the economy can service its foreign obligations and avoid a sharp, disorderly currency depreciation. The main indicators are the CAD, net foreign liabilities, the terms of trade and the exchange rate.
The current account records all transactions between Australian residents and the rest of the world that do not create a future financial claim, split into three sub-balances:
- Balance on goods and services - exports minus imports of physical goods and services (tourism, education, transport).
- Balance on primary income - interest, profits and dividends paid to and received from foreigners (mostly interest and dividend OUTFLOWS for Australia, given its net foreign liabilities).
- Balance on secondary income - transfers such as foreign aid and pensions paid overseas.
When outflows exceed inflows across these three sub-balances, Australia records a current account deficit (CAD), conventionally expressed as a percentage of GDP so that its size can be compared across years of different economic growth.
The four indicators, and the CAD formula every response needs.
The current account deficit (CAD) is the sum of the goods and services balance, the primary income balance and the secondary income balance, expressed as a percentage of GDP. Memorise the four indicators of external stability: the CAD (percent of GDP), net foreign liabilities (NFL = net foreign debt + net foreign equity, around 50 percent of GDP in 2024, ABS), the terms of trade (Export price index / Import price index x 100), and the exchange rate (AUD value, especially against the US dollar and the Trade Weighted Index).
Net foreign liabilities
Net foreign liabilities (NFL) measure the total stock of what Australia owes the rest of the world, net of what Australians own overseas. NFL has two components:
- Net foreign debt - money borrowed from foreigners that must be repaid with interest regardless of investment performance (e.g. Australian banks issuing bonds offshore).
- Net foreign equity - foreign ownership of Australian shares, property and businesses in exchange for a share of profits, with no fixed repayment obligation; the foreign investor bears more of the downside risk than a lender does.
Australia has run current account deficits for most of its post-war history, financed by foreign borrowing and equity investment, which is why net foreign liabilities have accumulated to around 50 percent of GDP in 2024 (ABS). A CAD funded by borrowing for productive investment (that lifts future export capacity) is generally judged less concerning than one funding consumption, because the former can service its own debt out of the extra income it generates.
The terms of trade
The terms of trade measures the ratio of export prices to import prices:
A rise in the terms of trade means a given quantity of exports buys more imports - effectively a national pay rise, since Australia earns more for what it sells without paying more for what it buys. Australia is a price taker for its major commodity exports (iron ore, coal, liquefied natural gas), so global commodity price swings, largely outside Australia's control, drive most of the volatility in the terms of trade and, in turn, the CAD.
The 2021 terms-of-trade boom (driven by very high iron ore and coal prices as global demand recovered from COVID-19 while supply stayed constrained) pushed Australia's current account into an unusually large surplus of 2.8 percent of GDP, its first sizeable surplus in decades. As commodity prices eased back through 2022-24, the terms of trade fell and the current account balance narrowed back toward, and then into, deficit by 2024.
The exchange rate
Australia has operated a floating exchange rate since 1983, meaning the Australian dollar's value is determined by market supply and demand rather than fixed by the government or the RBA. Key drivers of the AUD include the terms of trade, relative interest rates (higher Australian rates attract foreign capital, appreciating the dollar), and general market confidence in the Australian economy.
The Trade Weighted Index (TWI) measures the AUD's value against a basket of currencies of Australia's major trading partners, weighted by trade volume, giving a broader picture than a single bilateral rate like AUD/USD. The Australian dollar has fluctuated widely: from around US$1.10 in 2011 (near the peak of the mining investment boom) to the low US$0.60s range through parts of 2022-24 as the terms of trade eased and global interest rate differentials shifted.
A floating exchange rate is also an automatic stabiliser for the current account: a widening CAD tends to depreciate the dollar (as more AUD is sold to buy foreign currency to pay for imports and debt-servicing), which makes Australian exports more price-competitive and imports more expensive, gradually narrowing the deficit without any discretionary policy action.
- Read the data before you explain it
- For a data/stimulus item, state the DIRECTION and FIGURES first (e.g. "the current account balance rose from a deficit of 2.1% of GDP in 2019 to a surplus of 2.8% in 2021"), then explain the cause with a mechanism (e.g. a terms-of-trade boom lifting export income).
- Always separate debt from equity when discussing net foreign liabilities
- A NESA marker checks whether you recognise that equity investment shares risk with foreigners while debt must be repaid regardless; conflating the two caps an "assess the CAD" response mid-band.
- Use the exchange rate as the automatic stabiliser link
- Naming the floating exchange rate's self-correcting role (a widening CAD depreciates the dollar, which improves competitiveness and narrows the deficit) is the clearest way to show examiner-level understanding beyond describing the CAD in isolation.
Causes and consequences of external instability
Causes of a widening CAD / external instability:
- A fall in the terms of trade. Lower export prices (e.g. weaker Chinese demand for iron ore) reduce export income relative to import spending.
- Strong domestic demand for imports. Rising household income or a strong dollar increases import spending (consumer goods, overseas travel).
- Rising net foreign liabilities. Higher accumulated debt and equity stock increases primary income outflows (interest and dividends), which can widen the CAD independently of the trade balance.
- Global interest rate or confidence shocks. A rise in world interest rates raises debt-servicing costs; a loss of foreign investor confidence can trigger capital outflow and currency depreciation.
Consequences of external instability:
- Rising debt-servicing costs. Interest and dividend payments to foreign lenders and shareholders are a net primary income outflow that can itself widen the CAD, risking a "debt spiral" if new borrowing simply funds old debt-servicing.
- Exchange rate volatility. A sudden capital outflow can cause a sharp, disorderly depreciation, raising import prices (imported inflation) and complicating RBA monetary policy.
- Reduced future national income. A larger share of future output must be paid to foreign owners of debt and equity rather than staying available for domestic consumption or investment.
- Constrained policy settings. Persistent instability can pressure the RBA and government to prioritise external stability (e.g. supporting the currency) over other objectives like full employment, at least in the short run.
- Treating the CAD and net foreign liabilities as the same thing
- The CAD is a FLOW (the annual gap), while NFL is a STOCK (the accumulated total); a shrinking CAD still adds to NFL as long as it remains a deficit.
- Ignoring the debt-versus-equity split
- An "assess the CAD" response that treats all foreign liabilities as equally risky misses that equity investment shares risk with foreign owners, while debt must be repaid regardless of performance.
- Forgetting the exchange rate's automatic-stabiliser role
- Many students discuss the CAD as though only government policy can fix it, missing that a floating exchange rate self-corrects a widening deficit by depreciating and improving competitiveness.
- Quoting a stale CAD or NFL figure with no year
- Always date every figure (e.g. "a current account deficit of 0.3% of GDP in 2024", not just "Australia runs a CAD"); an undated statistic reads as guesswork to a marker.
- Confusing the terms of trade with the exchange rate
- The terms of trade is a ratio of export to import PRICES; the exchange rate is the price of the currency itself. They are related (a terms-of-trade boom tends to appreciate the dollar) but are distinct indicators.
Worked example - the 2021 terms-of-trade boom (data/stimulus style)
Question. Australia's current account balance moved from a deficit in 2019-20 to a surplus of 2.8% of GDP in 2021. Explain this shift using economic theory and current data.
Model answer. The shift to a current account surplus of 2.8% of GDP in 2021 is best explained through an exceptionally high terms of trade. As global demand recovered from the COVID-19 shock while commodity supply remained constrained, world prices for Australia's key exports, iron ore and coal, rose sharply. Because Australia is a price taker for these commodities, higher world prices directly lifted export income without any increase in the volume shipped, widening the balance on goods and services. At the same time, import spending grew more slowly, since international borders remained largely closed through 2021, cutting outbound tourism and education-related import-like spending. The combined effect of surging export income and subdued import spending pushed the current account from its usual deficit position into an unusually large surplus, illustrating how a favourable terms-of-trade shock can, at least temporarily, reverse Australia's structural current account deficit.
Marker's note: markers reward the terms-of-trade MECHANISM (world commodity prices to export income to trade balance), not just "exports increased". Full marks need the dated figure (2.8% of GDP surplus in 2021) and an explicit link to the price-taker status of Australian commodity exports.
Worked example - net foreign liabilities and the exchange rate (extended-response style excerpt)
Question. Explain how Australia's net foreign liabilities and its floating exchange rate interact to influence external stability.
Model answer. Australia's net foreign liabilities of around 50% of GDP (2024, ABS) generate ongoing interest and dividend outflows recorded in the primary income balance, which places continuing downward pressure on the current account. However, the floating exchange rate provides an important offsetting mechanism: as debt-servicing outflows and import spending push the current account toward deficit, increased demand for foreign currency (to make these payments) tends to depreciate the Australian dollar. A weaker dollar makes Australian exports cheaper for foreign buyers and imports more expensive for Australians, which gradually narrows the trade component of the deficit and helps offset the primary income drag, without the RBA or government needing to intervene directly in currency markets. This self-correcting relationship between accumulated foreign liabilities and the floating exchange rate is central to why Australia's external position, despite decades of current account deficits, has generally remained externally stable rather than triggering a currency crisis.
Marker's note: markers reward the LINK between the primary income outflow (from NFL) and the exchange rate's automatic-stabiliser response, with the dated NFL figure (around 50% of GDP, 2024) and the debt-servicing-to-depreciation-to-competitiveness chain made explicit, not just separate facts about NFL and the exchange rate.
Practice questions
Original practice questions graded from foundation to exam level, each with a full worked solution. Try them before revealing the solution.
foundation3 marksDefine external stability and identify the four main indicators used to measure it.Show worked solution →
A 3-mark "define and identify" needs the concept plus all four indicators.
Definition (1 mark). External stability means avoiding excessive fluctuations in Australia's external accounts and exchange rate, so that the economy can service its foreign obligations, maintain a sustainable current account deficit (CAD) and avoid a sharp, disorderly fall in the currency.
The four indicators (2 marks, half each). (1) The current account deficit (CAD) as a percentage of GDP. (2) Net foreign liabilities (NFL, debt plus equity) as a percentage of GDP. (3) The terms of trade (export prices relative to import prices). (4) The exchange rate (the value of the Australian dollar against other currencies, especially the US dollar, and the Trade Weighted Index).
foundation4 marksDistinguish between net foreign debt and net foreign equity, and explain how they combine to form net foreign liabilities.Show worked solution →
Award 1 mark per correct distinction (up to 2) and 2 marks for the combination.
- Net foreign debt (1 mark)
- Money borrowed from foreigners that must be repaid with interest, regardless of how the investment performs (for example, an Australian bank borrowing from an offshore bond market).
- Net foreign equity (1 mark)
- Foreign ownership of Australian shares, property and businesses in return for a share of profits or dividends; there is no fixed repayment obligation, so the foreign investor bears more of the risk.
- Combination (2 marks)
- Net foreign liabilities (NFL) = net foreign debt + net foreign equity. NFL is the broadest measure of what Australia owes the rest of the world net of what Australians own overseas, and is usually expressed as a percentage of GDP (around 50 percent of GDP in 2024, ABS) to judge whether the burden is manageable relative to the size of the economy.
core6 marksThe table below (ExamExplained, compiled from ABS Balance of Payments data, cat. no. 5302.0) shows Australia's current account balance as a percentage of GDP: 2019 negative 2.1%, 2020 negative 2.6%, 2021 positive 2.8%, 2022 positive 1.4%, 2023 positive 0.5%, 2024 negative 0.3%. Describe the trend shown, and explain the cause of the shift from surplus to deficit between 2021 and 2024.Show worked solution →
A 6-mark "describe and explain" rewards accurate reading of the data and a causal (not merely descriptive) chain, anchored in the terms of trade.
Describe the trend (about 2 marks). The current account moved from a deficit of 2.1% of GDP in 2019 to a slightly larger deficit of 2.6% in 2020 (the COVID-19 shock), then swung to an unusually large surplus, peaking at 2.8% of GDP in 2021, before narrowing steadily each year, falling to 1.4% (2022), 0.5% (2023) and back into a small deficit of 0.3% by 2024 - the first deficit since 2019.
Explain the 2021-24 shift (about 4 marks). The 2021 surplus was driven mainly by an exceptionally high terms of trade: booming iron ore and coal export prices (as global demand recovered from COVID-19 and supply was constrained) pushed export income well above import spending, producing a large primary income and goods surplus. As global commodity prices eased back from their 2021-22 peak and the terms of trade fell, export income growth slowed relative to import spending (particularly on services such as overseas travel, which rebounded strongly as international borders reopened), so the trade surplus narrowed. By 2024, softer commodity prices combined with continued strong import demand pushed the balance back into a modest deficit. The key mechanism markers want: a favourable terms of trade widens the current account surplus (or narrows the deficit) by lifting export income relative to import prices; an unfavourable shift does the reverse.
Marking spine: accurate figures with correct direction and sign (2), the terms-of-trade mechanism explicitly linked to export/import income (3), and at least one dated Australian data point beyond the table (1). A response describing the numbers with no terms-of-trade or import/export mechanism caps at 3.
core5 marksExplain how a fall in the terms of trade can worsen Australia's current account deficit, using an appropriate diagram or example.Show worked solution →
A 5-mark "explain" needs the terms-of-trade mechanism, a worked numerical or diagrammatic illustration, and a link back to the CAD.
- The terms of trade defined (1 mark)
- The terms of trade is the ratio of an index of export prices to an index of import prices, multiplied by 100: Terms of trade = (Export price index / Import price index) x 100. A rise means a given quantity of exports buys more imports; a fall means the opposite.
- The mechanism (3 marks)
- Australia is a price taker for its major commodity exports (iron ore, coal, LNG), so when world prices for these fall - for example, due to weaker Chinese steel production cutting iron ore demand - Australia earns less export revenue for the same volume of exports shipped. If import prices and volumes are unchanged, the trade balance (exports minus imports) narrows or moves into deficit, which widens the current account deficit, because export income is the main offsetting item against import spending and net primary income (debt-servicing) outflows in the current account.
- Illustration (1 mark)
- For example, if iron ore prices fall from around $120 to $80 a tonne while export volumes stay constant, total export earnings from iron ore fall by roughly a third, directly reducing the goods and services balance.
Marking spine: correct definition of the terms of trade (1), the price-taker mechanism linking a commodity price fall to lower export income (3), and one concrete numerical or diagrammatic illustration (1).
core6 marksOutline THREE consequences for the Australian economy of persistently high net foreign liabilities.Show worked solution →
A 6-mark "outline three consequences" needs three distinct, well-explained economic consequences (2 marks each).
- 1. Rising debt-servicing costs (about 2 marks)
- Interest and dividend payments owed to foreign lenders and shareholders are recorded as a net primary income outflow in the current account. As NFL grows, this outflow grows too, which can itself widen the CAD independently of the trade balance - a "debt spiral" risk if borrowing to fund the deficit simply adds to future servicing costs.
- 2. Exposure to global interest rate and confidence shocks (about 2 marks)
- A high level of foreign debt makes Australia more sensitive to rises in global interest rates (higher refinancing costs) and to shifts in foreign investor confidence; a sudden loss of confidence could trigger capital outflow and downward pressure on the Australian dollar, though Australia's foreign debt being mostly held by well-regulated banks and hedged reduces (but does not eliminate) this risk.
- 3. Reduced future national income (about 2 marks)
- A larger share of Australia's future output must be paid out as interest and profits to foreign owners of debt and equity, rather than being available for domestic consumption or investment, which can lower future living standards relative to a scenario with lower foreign liabilities.
Marking spine: three genuinely distinct consequences (up to 6, 2 each), each explained with a mechanism rather than just named. A response naming three near-identical ideas (e.g. all about "the dollar falling") caps at around 3.
exam8 marksAssess the extent to which a persistent current account deficit (CAD) is a serious problem for the Australian economy.Show worked solution →
An 8-mark "assess" needs a balanced argument (both a case for concern and a case for reassurance), dated Australian data/theory, and a clear final judgement.
Band 6 plan.
Thesis: A persistent CAD is a genuine but manageable structural feature of the Australian economy rather than an acute crisis, because it mainly reflects Australia's long-run comparative advantage in commodity exports interacting with a capital-hungry, fast-growing economy that must borrow from and attract equity investment from abroad to fund domestic investment beyond what national saving alone can finance.
Argument 1 - the case for concern. A large or rising CAD (Australia recorded a current account deficit of around 2 to 3% of GDP through much of the 2000s and 2010s, and moved back into a small deficit of around 0.3% of GDP in 2024 after the unusually large 2021 surplus) adds to net foreign liabilities each year it persists, and NFL was around 50% of GDP in 2024 (ABS). Growing net primary income outflows (interest and dividends paid overseas) can widen the CAD further, and a sudden loss of foreign investor confidence could trigger a sharp currency depreciation and higher import prices, which the RBA would then need to weigh against its inflation target.
Argument 2 - the case for reassurance. Much of Australia's foreign liability is equity rather than debt, and foreign equity investors share the risk of a downturn (unlike fixed-interest debt, which must be repaid regardless), so the "twin deficits" framing of the 1980s-90s overstates today's risk. The floating exchange rate acts as an automatic stabiliser: a widening CAD tends to depreciate the dollar, which makes exports more price-competitive and imports more expensive, gradually narrowing the deficit without requiring discretionary policy action - as seen in the dollar's fall from around US$1.10 in 2011 to the low US$0.60s range through parts of 2022-24.
Counter-weight / judgement: The CAD is best read alongside the composition of foreign liabilities (debt versus equity) and what the borrowing funds (productive investment versus consumption) rather than the headline number alone; a CAD funding productive investment that lifts future export capacity is far less concerning than one funding consumption, so the current Australian CAD, moderate in size and predominantly financing productivity-enhancing investment, is a manageable structural feature rather than a crisis.
Model paragraph. Australia's return to a small current account deficit of around 0.3% of GDP in 2024, after an unusually large 2.8% of GDP surplus in 2021 driven by a historically high terms of trade, illustrates why the CAD is best understood as a structural feature of the economy rather than an emergency. The floating exchange rate provides an important automatic stabiliser: as the terms of trade eased back from its 2021-22 peak and the current account narrowed, the Australian dollar's flexibility (trading in the low US$0.60s through parts of 2022-24, down from around US$1.10 in 2011) helped keep Australian exports price-competitive, cushioning the adjustment. While net foreign liabilities of around 50% of GDP (2024, ABS) do carry genuine debt-servicing and confidence-shock risks, the fact that a large share of this liability is equity rather than fixed-interest debt means foreign investors, not just Australian taxpayers, bear much of the downside risk. On balance, a moderate, well-composed CAD financing productive investment is a manageable feature of a capital-importing, resource-exporting economy rather than a serious economic problem.
Marker's note: markers reward a genuinely BALANCED assessment (both risk and reassurance, not a one-sided answer), the debt-versus-equity distinction, the exchange-rate automatic-stabiliser mechanism, dated Australian data (2021 surplus of 2.8% of GDP, 2024 deficit of 0.3% of GDP, NFL around 50% of GDP), and an explicit final judgement. A response that only lists causes of the CAD with no assessment of "how serious" stays mid-band.