One way to have broader access to wealth is to reduce the tax on the large group and increase the tax on the very top so concentration of wealth doesn't get to extreme levels.
We know too little about global wealth dynamics, so we need international transmission of bank information.
I am afraid that if you don't find peaceful domestic solutions to our inequality and social problems, then it's always tempting to find other people responsible for our problems.
What I argue for is a progressive tax, a global tax, based on the taxation of private property.
Private property and the market system are good not only to promote innovation and to promote growth; private property and the market system are good for our personal freedom.
When inequality gets too extreme, then it becomes useless for growth, and it can even become bad because it tends to lead to high perpetuation of inequality over time and low mobility.