This sort of logic just fails to understand human behavior. First off, you make the terrible assumption that there will be more people earning at least double $

This sort of logic just fails to understand human behavior. First off, you make the terrible assumption that there will be more people earning at least double $X so that you can take half of it to give to another that isn't making X. That's nowhere even close to a 50-50 split, and this policy would make it even less even not more. You cannot tax yourself to prosperity. All you are doing is taking money from the people that are producing and giving to the people who are not in the hopes that they might suddenly decide to be entrepreneurial with their newfound financial freedom. Guess what, that desire to become financially free is a far stronger motivator.