The billionaire tax and the paradox of idle wealth

California Governor Gavin Newsom has called, according to CNBC, for "a true minimum tax on billionaires" and the closing of what he terms "tax-free lifestyle loan" loopholes — arrangements by which the very wealthy borrow against unrealised asset gains, spend freely, and pay nothing to the revenue in the process. He frames this as an "economic reset." The phrase is vague, as political phrases tend to be, but the underlying economic question is sharper than the slogan suggests, and it is one I find impossible to ignore.

The orthodox objection will arrive promptly: tax the wealthy and you tax the capital that funds investment; restrain the accumulation of great fortunes and you restrain the animal spirits that drive enterprise. I take this argument seriously, because animal spirits are real — confidence, expectation, the narrative that surrounds a business venture — these things matter enormously to whether investment actually occurs. But the argument proves too much when pushed to its limit. Capital that is permanently locked inside appreciating assets, borrowed against for consumption without ever being realised as taxable income, is not circulating through the productive economy. It is, in the macroeconomic sense, being hoarded — not in a mattress, but in a structure of financial arrangements that achieves the same demand-suppressing result.

Here the paradox of thrift reasserts itself at the scale of an entire class. What is rational for any individual billionaire — to hold, to borrow, to defer the taxable event indefinitely — becomes, in aggregate, a sustained withdrawal of purchasing power from the circuit of the economy. The household analogy that dominates popular fiscal debate — the notion that a prudent nation must behave as a prudent family — misses this entirely. A family that saves during a downturn acts wisely; a society in which all families save simultaneously produces a collapse of demand. The same logic applies, with compounding force, when the saving is done by those whose marginal propensity to consume is lowest of all.

Governor Newsom's specific mechanism — closing the "tax-free lifestyle loan" loophole — is, on its face, the more tractable reform. I defer on the precise engineering of any modern tax code, because the institutional details of American federal taxation evolved well after my time, and I would not pretend to technical authority I do not possess. But the macroeconomic principle is clear enough: if a tax system permits indefinite deferral of liability on unrealised gains while simultaneously permitting those gains to fund consumption through borrowing, it is not merely inequitable — it is structurally biased against the circulation of income, and therefore against demand.

The moral case and the macroeconomic case converge here, which is the kind of alignment a policymaker should not waste. Full employment — not merely low inflation, not merely a balanced budget — is the correct target of economic governance, and it requires that income move through the economy rather than pool at its summit. Whether Governor Newsom's proposal is the right instrument, at the right rate, structured in the right way, I cannot say with confidence from this distance. What I can say is this: the question he is raising is a real one, the instinct is sound, and anyone who dismisses it by invoking the sanctity of capital formation without examining what that capital is actually doing deserves a rather careful cross-examination.