What macroeconomics is trying to explain

Most investors meet macroeconomics as a stream of headlines: a payrolls number, a central bank decision, a downward revision to growth in the euro area. The headlines are the exhaust, not the engine. Macroeconomics is the attempt to explain why the total output of an economy — everything produced by everyone in it — rises, falls, and grows over decades, and why the price of that output changes. Everything else in this course is an elaboration of those questions.

The reason the subject is hard, and the reason it cannot be done by scaling up your intuitions about a household or a firm, is that at the aggregate level nobody's spending is independent of anybody else's income. Your expenditure is someone's revenue; their revenue funds their expenditure, which is someone else's revenue. A single firm can cut costs and become more profitable. All firms cutting costs simultaneously reduce the wage income out of which their customers buy things. That circularity is the whole discipline, and it is why the answers are counterintuitive often enough to be worth learning properly.

The fallacy of composition, with numbers

The classic illustration is the paradox of thrift. Take a closed economy with no government and no trade. Households consume a fixed fraction of income; firms invest a fixed amount, financed by borrowing, independent of current income. Say consumption is 90% of income and investment is 10 units.

Equilibrium income is where output equals demand: Y = 0.9Y + 10, so 0.1Y = 10 and Y = 100. Households save Y − C = 100 − 90 = 10, which exactly matches investment of 10.

Now suppose households become cautious and decide to save 20% rather than 10% of income. Consumption becomes 0.8Y. The new equilibrium is Y = 0.8Y + 10, so 0.2Y = 10 and Y = 50. Saving is now 50 − 40 = 10 — identical to before. The saving rate doubled; total saving did not move at all; income halved.

The mechanism is not mysterious. Saving is income not spent. If the only thing that adjusts is income, then a higher desired saving rate is satisfied by a lower income rather than by more saving. In the real world investment is not fixed and other sectors absorb the shift, so the effect is milder. But the direction is real, and it is the reason a recession can be caused by everyone behaving prudently at once. This is a fallacy of composition: an inference that is valid for one participant and invalid for all of them together.

Identities are not theories, but you must respect them

A handful of accounting relationships hold by construction, regardless of what you believe about how the economy works. They constrain any story you tell.

Output equals expenditure: Y = C + I + G + (X − M) — consumption, investment, government purchases, and exports minus imports. Rearranged, this gives the sectoral balances identity: the private sector's financial surplus, the government's deficit, and the current account balance must sum in a fixed way. If the domestic private sector wants to save more than it invests, and the government refuses to run a deficit, the surplus can only be absorbed abroad — the country must run a current account surplus, which requires someone abroad to run a deficit.

Switzerland lives at one pole of this identity. It runs a persistent current account surplus, which is the accounting counterpart of domestic saving — households, pension funds, and highly profitable corporates — exceeding domestic investment. That surplus is not a moral achievement or a policy target; it is the arithmetic shadow of a high-saving, capital-exporting economy. It also explains why Swiss investors are structurally long foreign assets and therefore structurally exposed to the franc.

Identities cannot tell you which variable adjusts. That is what a model is for, and it is where economists disagree. But an argument that violates an identity is simply wrong, and a surprising number of published arguments do.

Three questions, three time horizons

Macroeconomics is really three subjects wearing one name.

Long-run growth. Why does output per person in Switzerland exceed that in Portugal by a wide margin, and why did both grow enormously over the past century? The answer runs through capital accumulation, human capital, institutions, and above all productivity — output per hour worked. Over a horizon of decades, nothing else matters much. The sibling lesson on productivity develops this.

Short-run fluctuations. Why does actual output deviate from what the economy could sustainably produce, for periods of quarters to years? Here demand, credit, expectations, and policy dominate. Prices and wages do not adjust instantly, so shocks show up as changes in quantities — output and employment — rather than only in prices. This is the domain of the business cycle.

The price level. Why does the general level of prices rise, at what rate, and what determines expectations of future inflation? Inflation is where the short run and the long run collide, and it is the variable that most directly sets the discount rate applied to every asset you own.

Confusing the horizons is the single most common error in market commentary. A supply-side argument about long-run growth tells you nothing about next year's earnings. A demand-side argument about the next two quarters tells you nothing about the standard of living in 2050.

Why an investor should care at all

An asset price is a claim on future cash flows, discounted. Macroeconomics touches both halves.

The numerator — corporate earnings, rents, tax receipts — is a share of aggregate output. Aggregate output is what macro explains. The denominator — the discount rate — is built from the real risk-free rate, expected inflation, and risk premia, all of which are macro variables. So macro does not merely "affect markets" at the margin; it is most of what determines the level of a diversified portfolio's value.

Macro also governs correlations. Whether bonds hedge equities depends on whether the dominant shocks are to demand or to supply. When demand is the driver, weak growth and low inflation arrive together: bonds rally while equities fall, and the classic balanced portfolio works. When supply is the driver — an energy shock, a disruption to trade — output falls while prices rise, and bonds and equities can fall together. Investors who learned diversification during one regime routinely discover this the hard way in the other. The lesson on stagflation goes into the policy trap this creates.

The Swiss case: a small open economy with a hard currency

Swiss macro has features that do not transfer from American textbooks.

Switzerland is small and open. Exports and imports are large relative to GDP, so foreign demand — the euro area above all, then the United States and Asia — drives the Swiss cycle more than domestic policy does. Leading indicators for Germany often lead Switzerland.

The franc is a safe-haven currency. In global risk-off episodes it tends to appreciate precisely when Swiss exporters are already facing weak foreign demand — an unhelpful correlation, and the reason the Swiss National Bank has intervened in foreign exchange markets and, for a period after 2011, enforced a minimum exchange rate against the euro. The SNB's mandate is price stability while taking account of economic developments; it has defined price stability as inflation below 2% per year, and it has historically run inflation nearer the bottom of that range than its peers.

Currency appreciation also imports disinflation. A stronger franc mechanically lowers the franc price of imported goods, which is part of why Swiss inflation has typically been lower and less volatile than in neighbouring economies. For a Swiss-resident investor this matters twice: it holds domestic inflation down, and it erodes unhedged foreign returns.

The arithmetic is worth internalising. Suppose a global equity fund returns 8% in US dollars over a year while the franc appreciates 5% against the dollar. Your return in francs is 1.08 / 1.05 − 1 = 2.86%. The macro variable ate nearly two-thirds of the equity return. Over long periods that drag has been substantial for unhedged Swiss investors, and it is a macro question, not a stock-picking one.

What macroeconomics cannot do

It cannot forecast turning points reliably. Recessions are, by construction, moments when behaviour changes discontinuously; a model estimated on the previous regime will miss them. The professional use of macro is not prediction but conditioning: knowing which state the economy is plausibly in, what would have to be true for a given scenario, and which data would falsify your view.

It also cannot be tested cleanly. There is one economy, running one history, with no control group. Identification comes from natural experiments, cross-country comparison, and theory — all weaker than a randomised trial. Treat any macro claim stated with laboratory confidence as a claim about the speaker rather than the world.

What to take away

• Aggregate outcomes are not the sum of individual intentions: a higher desired saving rate can leave total saving unchanged while halving income, because one agent's spending is another's income.
• Accounting identities such as Y = C + I + G + (X − M) and the sectoral balances constrain every macro argument, but they never tell you which variable does the adjusting — that requires a model, and models disagree.
• Long-run growth, short-run fluctuations, and the price level are three separate problems with different mechanisms; most bad commentary comes from answering one with the tools of another.
• Macro sets both the numerator and the denominator of asset valuation, and it also determines whether bonds and equities hedge each other — demand shocks make them offset, supply shocks make them move together.
• For a Swiss-resident investor the franc is a macro variable inside every foreign holding: an 8% dollar return alongside a 5% franc appreciation leaves 2.86% in francs.

Sources

• Olivier Blanchard, Macroeconomics (Pearson) — standard intermediate treatment of identities, the short run and the long run.
• N. Gregory Mankiw, Macroeconomics (Worth Publishers) — parallel treatment with extensive worked national-accounts material.
• Swiss National Bank, monetary policy assessments and the Quarterly Bulletin — the SNB's own statements of its mandate and its definition of price stability.
• State Secretariat for Economic Affairs (SECO), quarterly GDP releases and commentary on the Swiss business cycle.
• Swiss Federal Statistical Office (FSO), national accounts and balance of payments statistics.
• Wynne Godley and Marc Lavoie, Monetary Economics: An Integrated Approach to Credit, Money, Income, Production and Wealth (2007) — rigorous development of the sectoral balances framework.
• Bank for International Settlements, Annual Economic Report — recurring analysis of small open economies, capital flows and safe-haven currencies.