"Economics and history both strive to understand causation: economics using instrumental variables econometrics and history by weighing the plausibility of alternative narratives. Instrumental variables can lose value with repeated use because of an econometric tragedy of the commons bias: each...

"The fundamental unit of production in microeconomics is the firm, and this mirrors reality in the United States and United Kingdom. But elsewhere, business groups can be the more important unit, for business strategy is often formulated at the business group level, not the firm level. In many...