Step 4b of Pedro’s DID checklist: Difference-in-Differences, Selection Mechanisms and Parallel Trends After Earth's Great War

I’ve been binging “The Expanse” on Amazon Prime, a world-building science fiction show set several hundred years into the future. It involves space conflict between Mars, Earth, and a group of ragtag workers mining in an Asteroid Belt. Created by some of the minds behind “Game of Thrones,” it’s an addictive story that kept me up until 2:30 am last night…