> How, exactly, do you expect the government to tally the amount of wealth to be taxed for each person in the country?
Ask and audit, the same way it does income. Of course, it's harder to get filed confirmation data for wealth and even easier to have an alternative valuation for wealth held in non-cash assets than for realized income, so it will be much easier to evade, but that's probably part of why it (which complicates our overall system of taxation) rather than taxing the currently tax-favored income of the rich, primarily capital gains, at the same rate as other income (which would simplify the tax system) is favored by people whose concern is to be seen as doing something about tax fairness.
I think by "easier to evade" you actually mean "impossible to enforce". The sorts of things the wealthy store their money in aren't easy or even possible to value, especially on some yearly basis.
Ask and audit, the same way it does income. Of course, it's harder to get filed confirmation data for wealth and even easier to have an alternative valuation for wealth held in non-cash assets than for realized income, so it will be much easier to evade, but that's probably part of why it (which complicates our overall system of taxation) rather than taxing the currently tax-favored income of the rich, primarily capital gains, at the same rate as other income (which would simplify the tax system) is favored by people whose concern is to be seen as doing something about tax fairness.