Pop quiz: Name this leftist economist.

He believed that government had a crucial role to play in a well-functioning economy. It should finance and run good schools, as well as build roads, bridges and parks, he argued. It should tax alcohol, sugar and tobacco, all of which impose costs on society. It should regulate businesses to protect workers. And it should tax the rich — who suffer from “indolence and vanity” — to help the poor.

If you guessed Adam Smith, you're right.