If one imposes a 50-percent tax on billionaires.....whatever it is that they run/manufacture...will increase to the level to pay for that tax. In reality, You could be talking about a Burger King menu bag worth $11 today...costing $32 in this world of reality. And if they can’t achieve that...they will cease their product production and go someplace else to make it.
most billionaires net worth is in stocks, to pay this tax they would have to sell large portions of their stock collapsing stock markets around the world and throwing the world into a depression.