More than 1bn people around the world are obese. That means there should be extraordinary demand for drugs to cure or mitigate the condition. Novo Nordisk is now Europe’s most valuable company and Eli Lilly’s market value has more than doubled. Both make the “miracle” drugs that can help people...

Amazon started with a plan to disrupt bookselling. It sold cheap books online, delivering them straight to customers’ homes. Three decades later it employs a million people in America and owns one hundred warehouses, each stocked with millions of products. More than a third of the US e-commerce...