It's no secret that international trade has been criticized lately. But why exactly are countries generally happy to trade within their borders -- from one state or town to another, for example -- but more reluctant to trade across international ones? And why are countries so focused on making things domestically? On this edition of the Odd Lots podcast we speak to an over-achiever in the field of economics who specializes in trade and is known for rigorous research that has included poring over railway records from the British Raj era in India. Dave Donaldson is the most recent recipient of the prestigious John Bates Clark Medal awarded to economists under the age of 40. He speaks about what he learned from studying trade across history and what exactly it has to offer in modern times.