Volume I closed by tracing one iPhone’s journey through the system it had built (Volume I §12.1). Volume II closed with three practitioner cases (Volume II §12.2–12.4). This Part does the same with three cases that each need all three volumes: a rate shock that turns into a recession (Part 10.2: Case One — A Global Recession, Fully Traced), a US solar project financed and taxed under the rules in force in October 2026 (Part 10.3: Case Two — Financing a Renewable Infrastructure Deal), and an emerging-market currency crisis (Part 10.4: Case Three — A Sovereign Debt Crisis, Fully Traced). Each case runs the same way: the situation, the numbers, a decision someone has to make, and the outcome under the scenarios that matter. The aim is not recall of a single fact but the ability to follow one situation across the width of finance — and to notice when a wrong mechanism, rather than a wrong number, would have produced the wrong decision. Case One shows exactly that: get the effect of rising rates on an insurer’s liabilities backward and the right decision turns into the wrong one.
The table shows where each case draws its tools. Parts 5, 8 and 9 of this volume, which are easy to treat as niche side roads, sit on the main line of the cases: microstructure decides what a forced sale costs, reconciliation decides whether a collateral call or a cash waterfall is right, and the history of ideas explains why governments respond to a recession the way they do.
| Case | This volume | Volume I | Volume II |
|---|---|---|---|
| One — rate shock to recession (10.2) | Parts 1, 2, 3, 5, 6, 8, 9 | Vol I §2.3 The Federal Reserve; Vol I §2.9 Bonds and the Yield Curve | Vol II §3.2 Duration; Vol II §3.5 Inversions; Vol II §2.5 Leverage |
| Two — financing a solar plant (10.3) | Parts 1, 2, 4, 7, 8 | Vol I §1.17 Climate Economics | Vol II §1.3–1.4 DCF and WACC; Vol II §8.5 Real Assets; Vol II §6.5 Deferred Tax |
| Three — a currency crisis (10.4) | Parts 3, 5, 8, 9 | Vol I §9.4 Sovereign Default; Vol I §10.1 The 1991 Crisis | Vol II §4.1 Forwards; Vol II §4.8 Hedging vs Speculation; Vol II §10.3 The Asian Crisis |
All three cases are built on illustrative companies and countries, so that every number can be shown and checked; the rules, market events and research they rely on are real and dated.
The case method. When you meet a new situation, work it in four steps. First, name the balance sheets that move: whose assets, whose liabilities, whose cash. Second, find the one variable that moves them all — usually a discount rate, an exchange rate or a tax rule. Third, compute the effect at three or more values of that variable and find the flip point, where the answer changes sign. Fourth, decide, and decide against the scenario you could not survive rather than the one you expect. Skip the third step only when the decision can be reversed quickly and cheaply.