The Undercover Economist

Harford applies price theory to ordinary transactions: the cost of a cappuccino near a train station, the pricing tiers on a supermarket shelf, the market for secondhand cars, health insurance in the United States, and the auction of 3G spectrum in Britain. Each chapter takes a familiar situation and shows which economic mechanism explains it.

The recurring themes are scarcity power, price discrimination, information asymmetry and externalities. Harford argues that most of what looks like corporate greed is actually rent extracted from a scarce input, usually location or a regulatory barrier, and that firms spend enormous effort separating customers by willingness to pay. He works through Akerlof's lemons model to explain why used-car and insurance markets break down, and uses Coase and Pigou to argue for pricing externalities rather than banning them. The final chapters cover why some countries stay poor, leaning on institutional and corruption arguments, and why China's reforms worked.

The book is an introduction, not a contribution. It rests on standard microeconomics and a set of well-chosen illustrations rather than original research, and it is useful for pricing intuition, for thinking about where margin actually comes from, and for spotting adverse selection in a business model. Its policy positions sit firmly in the market-liberal tradition of the mid-2000s and have aged less well: the treatment of globalisation and sweatshops is confident in ways that later empirical work has complicated, and the pre-2008 confidence about financial markets is visible throughout.