@Koenfucius #naturalexperiments are under way … just unplanned and sometimes unethical …

RT @fetzert@twitter.com

What is the epidemiological impact of a #falsenegative #COVID test? An important question in a high vaxx/low NPI context, but one that cannot be studied in a experiment for obvious reasons. Enter the UK, a reliable supplier of #naturalexperiments. 🧵⬇️
➡️https://bit.ly/3DhqQv5

🐦🔗: https://twitter.com/fetzert/status/1460166688423489538

Section 2 asks a fundamental question: where do valid #instruments come from?

#BEE2031 #IVRegression #naturalexperiments