The global supply chain that keeps perishable goods at controlled temperatures has revolutionised the food industry. It widened our choice of food and improved our nutrition. It enabled the rise of the supermarket. And that, in turn, transformed the labour market: less need for frequent shopping frees up women to work. As low-income countries get wealthier, fridges are among the first things people buy: in China, it took just a decade to get from a quarter of households having fridges to nearly nine in ten.

Presenter: Tim Harford

(Image: Fully loaded shelves, Credit: Shutterstock)