What is the Glasgow effect? Richard Davies explains, and tells the gripping economic story of how shipbuilding drove the Scottish city’s boom and bust. Drawn from his new book Extreme Economies (Farrar, Straus and Giroux 2020), they begin by describing how the economic forces of Marshallian externalities led to the rise of Glaswegian shipbuilding on the River Clyde. They then turn to its tragic downfall, its economic and social policy failures, and the extremely low life expectancy plaguing Glasgow to this day.