Norway 🇳🇴 put about 300 million dollars into its fund in 1996. Thirty years later, it's worth 2.3 trillion. And the curious thing is that most of it isn't oil—it's returns. Compound interest straight out of a textbook.

Today, that fund holds an average of 1.5% of all publicly traded companies in the world. The government can only withdraw around 3% a year, which generates income without touching the principal. And with that, it covers more than a quarter of the budget's spending...