This morning, I'm speaking to one of Mike Munger's classes at Duke about Walmart and the importance of trade. Here are a few resources.
1. An ungated version of my paper "Retail Innovations in American Economic History," which appeared as a chapter in the Routledge Handbook of Major Events in Economic History.
2. The talk on Walmart I gave at Middle Tennessee State University in 2011:
3. The talk on Walmart I gave in Brazil earlier this year, including a few words on Munger:
Edit, 7:26 PM Central: Here's a link to my papers on Walmart.