Part VII — Macroeconomic Fluctuations and Policy
Booms, busts, and what governments can (and can't) do about them.
Economies don't grow in a straight line. They expand for a few years, slow, sometimes contract, recover, and grow again. The pattern is so consistent that economists have a name for it (the business cycle) and a national agency (the National Bureau of Economic Research) that officially dates the start and end of every recession. But the causes of recessions are not consistent. Some are demand shocks. Some are supply shocks. Some are both. The 2008 Great Recession was a financial crisis. The COVID recession was a public health shock. The early-1980s recession was caused by the Federal Reserve deliberately tightening to break inflation. No two are quite alike.
The four chapters in Part VII take you from the descriptive question (what is the business cycle and why does it happen?) to the analytical question (how can we model what happens during a recession?) to the policy question (what can the government and the central bank do, and what should they do?). By the end of the part, you should be able to look at a real economic episode — the 2008 financial crisis, the COVID recession, the 2021–23 inflation surge, the 2010s "secular stagnation" debate — and analyze it with the tools of aggregate demand and aggregate supply, fiscal policy, monetary policy, and open-economy macro.
Chapter 30 — The Business Cycle introduces expansion, peak, recession, and trough; leading, lagging, and coincident indicators; and the distinction between demand shocks and supply shocks. The chapter walks through 2008 and COVID as case studies in two completely different kinds of recession — both within fifteen years — and is honest about how that should chasten anyone's confidence about predicting the next one.
Chapter 31 — Aggregate Demand and Aggregate Supply is the central macro model and the longest chapter in Part VII. The chapter builds the AD curve carefully (three reasons it slopes downward), distinguishes short-run from long-run aggregate supply, and walks you through how to use the model to analyze a demand shock, a supply shock, and a stagflation scenario. The Keynesian vs. classical debate becomes concrete here: classicals think the economy self-corrects to full employment in the long run; Keynesians think the long run can be very long. Both are right under different conditions. COVID — a simultaneous demand shock and supply shock — is the running example because most macro models assume one shock at a time, and COVID wasn't kind to that assumption.
Chapter 32 — Fiscal Policy walks through what governments do with spending and taxes to influence the economy. Automatic stabilizers (unemployment insurance, progressive taxes) vs. discretionary policy (stimulus packages). The multiplier and why empirical estimates of its size vary so widely. The relationship between deficits, debt, and crowding out — with the qualification that crowding out is small at the zero lower bound. The 2009 ARRA stimulus. The 2020–21 COVID relief packages. The austerity debate and the lessons from the Reinhart-Rogoff coding error. Where economists disagree honestly.
Chapter 33 — The Open Economy scales the macro model up to the international level. The balance of payments. Exchange rate determination. Fixed vs. floating regimes. The impossible trinity (a country can have any two of: fixed exchange rate, free capital mobility, independent monetary policy — but not all three). Currency crises: the Asian financial crisis (1997), the eurozone crisis (2010–13). China's exchange rate policy and the dollar's role as the world's reserve currency.
When you finish Part VII, you have the full macroeconomic toolkit. Part VIII turns to the contemporary topics that most other introductory textbooks barely cover.