Economics & Finance / Macroeconomics / International Trade & Globalization

70% of Britain's 1930s trade shift was engineered by tariffs, not history. Here's the proof.

In the 1930s, Britain's trade with its empire surged from 27% to 39%. For decades, historians thought this was just natural economic gravity—old colonial ties and currency links. But a groundbreaking study by Alan de Bromhead, Alan Fernihough, Markus Lampe, and Kevin Hjortshøj O'Rourke crunched 258 product categories and 42 countries to reveal the truth: 70% of that shift was caused by deliberate protectionist policies, like the 1932 Import Duties Act and Ottawa Agreements. They even ran a counterfactual—if Britain had stayed free trade, empire imports would have collapsed to just 13%-25%. This video breaks down the data, the hidden power of quotas (equal to a 21.5% tariff on meat), and why this matters for today's trade wars. You'll see how governments can reshape global supply chains overnight.