Can Lego save the world? That’s one idea that stuck with me reading How Big Things Get Done, a new book by Bent Flyvbjerg and Dan Gardner. Flyvbjerg is perhaps the world’s leading authority on the failure of megaprojects – or how big things get done, but woefully late and at woeful cost – and so he makes an unlikely optimist.

Over the decades, Flyvbjerg, a management professor at Oxford university, has assembled a database of large projects from high-speed rail lines to hosting the Olympics.