Economists Saez, Zucman, etc. propose: "Ending Corporate Tax Avoidance and Tax Competition: A Plan to Collect the Tax Deficit of Multinationals." Countries would charge an additional tax on profits that are undertaxed in other countries. https://eml.berkeley.edu/~saez/CSZ2020.pdf …
"Between 1985 and 2019, the global average statutory corporate tax rate has fallen from 49 percent to 23 percent, largely due to the rise of international tax competition." (i.e. Corporate tax rates are chosen to be competitive but not necessarily equitable.) We need equity...