A realistic wealth tax probably caps out and around 2%, remembering that the net worth of very rich people is generally not liquid and can be difficult to mark to market. Any higher rate risks forcing the rich to have an asset fire sale, which liquidates productive assets and isn't really good for anybody. At six to seven percent you would force them to be entirely liquid and would begin to shrink their wealth, killing off the tax base in a few generations. Even this is absurdly optimistic since a globally standardized wealth tax is a pipe dream and without it you get capital flight as a result of any wealth tax at all, but let's ignore that.
To steelman this as much as possible let's say you can charge 6%. The top 0.5% are worth $30-$40 trillion in the U.S. (which is just an easy example because the statistics are available) which gives you a probably unrealistically high max annual tax revenue of $2.4 trillion. Social Security and Medicare in their current form cost $1.35 trillion a year; Medicare for All would double to triple that or more, depending on what estimate you believe.
Europeans pay for their social safety nets with very broad taxation while America instead charges negative income tax (after credits) to the bottom 60 percent of the population (even after inflation, excise taxes, state tax, payroll tax and tariffs the total tax burden is pretty slim at the bottom end by European standards). There doesn't seem to be a mathematically feasible way to give benefits to the working class that the working class doesn't pay for.
You're probably right, though U.S healthcare costs per capita are much higher than they need to be, and would be much lower in a "proper" single payer system like in Europe. In any case, a wealth tax would still help a lot with being able to fund these programs. Yes, the working class does have to pay as well, but it'd be much less if there were a reasonable wealth tax.
But yes, global co-operation to enable a large enough tax on wealth is not going to happen any time soon. A more likely scenario is that as automation develops and as the share of income that capital gets grows, the working class will end up in a position bad enough that capitalism will collapse and be replaced with something else. Hopefully with something better, but could also be worse.
A realistic wealth tax probably caps out and around 2%, remembering that the net worth of very rich people is generally not liquid and can be difficult to mark to market. Any higher rate risks forcing the rich to have an asset fire sale, which liquidates productive assets and isn't really good for anybody. At six to seven percent you would force them to be entirely liquid and would begin to shrink their wealth, killing off the tax base in a few generations. Even this is absurdly optimistic since a globally standardized wealth tax is a pipe dream and without it you get capital flight as a result of any wealth tax at all, but let's ignore that.
To steelman this as much as possible let's say you can charge 6%. The top 0.5% are worth $30-$40 trillion in the U.S. (which is just an easy example because the statistics are available) which gives you a probably unrealistically high max annual tax revenue of $2.4 trillion. Social Security and Medicare in their current form cost $1.35 trillion a year; Medicare for All would double to triple that or more, depending on what estimate you believe.
Europeans pay for their social safety nets with very broad taxation while America instead charges negative income tax (after credits) to the bottom 60 percent of the population (even after inflation, excise taxes, state tax, payroll tax and tariffs the total tax burden is pretty slim at the bottom end by European standards). There doesn't seem to be a mathematically feasible way to give benefits to the working class that the working class doesn't pay for.