These accounts are certainly not perfect. For example, at the world level, the net financial position is negative overall, which is logically impossible unless we assume that on average we’re owned by the planet Mars. More likely, this contradiction suggests that a nonnegligible share of financial assets held in tax havens and by nonresidents is not correctly reported as such. Among other things, this affects the net external position of the Eurozone, which is probably much more positive than official statistics suggest, as the economist Gabriel Zucman has recently shown. Well-off Europeans have every interest in hiding assets, and the European Union for the moment isn’t doing what it should—and could—to deter them.

The second thing to note is that while the Japanese government certainly has a gross debt in excess of 200 percent of GDP, it owns nonfinancial assets on the order of 100 percent of GDP (real estate, land), as well as financial assets also on the order of 100 percent of GDP (ownership stakes in public companies, savings banks, and quasi-public financial institutions). So assets and liabilities more or less balance.