> If there are 100 billionaires, and you tax 2% more, and 1 billionaire moves away, you're still up on revenue. I often hear people arguing that we should operate our government more like a business.

This is actually one of the standard strategies for taxation: we should setup a tax system that optimizes for the maximum total tax receipts. When you tax too much, incentives go down and you actually lower your total tax receipts. In principle, there is an optimal taxation amount.

The problem with this approach is that we don't have good enough data. No one really knows how many fewer billionaires there would be if we increased their taxes, and biased interests each have plenty of conjured data to make their argument.

There are other tax strategies as well: trickle down economics (a favorite of the right, also based on suspect data); and guaranteeing living wage (a favorite of the left). One advantage of the latter is that the argument is not based on numbers or data, but on morality.