Tag Flip

You run the trade desk at the Exchange Gate, between Britain's Port of Glenhaven and America's Port of Bayview. Every cargo ship stops at the gate, and when the pound appreciates or depreciates you flip its price tag up or down: what do American buyers now pay in dollars, and UK shoppers in pounds? Then call what happens to demand for exports and imports and watch the UK's current account tip towards surplus or deficit. Later the government fixes the rate, and you meet revaluation and devaluation.