I think that an "increase in wealth" tax might be accomplished by taxing income, but deducting all consumer spending. If you earn $70k and spend $60k on rent,

I think that an "increase in wealth" tax might be accomplished by taxing income, but deducting all consumer spending. If you earn $70k and spend $60k on rent, utilities, groceries, car repairs, and such, then $10k is taxable. If you earn $40k and spend $40k, essentially living paycheck-to-paycheck, $0 is taxable. If you earn $300k and spend $100k, then $200k is taxable. Purchase of financial instruments and equities are not deductible. If you add to that an exemption of the higher of 5% of income or $20k--so as to not punish people for having a reasonable savings rate--and progressively tax the remainder, that seems pretty "fair" to me (aside from the question of whether any tax can be truly fair). Those who end up paying it are only the ones who can afford to pay it, and they pay in proportion to the extent to which they benefited from the economy. This kind of tax, like any other, also has possible unintended consequences.