Peer-to-peer platforms have changed the game. Make them cheap or free, and it would be way of reinventing the economy to deliver participation and choice alongside social justice
»Economists came to describe this benefit of collaboration as a “positive externality”. And the clue is in the name. It’s good, but it comes from somewhere outside the strict market relationship between two parties in a contract. The next problem is how to quantify the benefit – and decide who should own it.«











