> The thing is, when you hoard wealth as numbers on a balance sheet rather than spending it, you are actually destroying that wealth. Money which is not in motion is not money.
This money is not simply sitting under a mattress. It's being reinvested, often in low risk treasury bonds, lowering the cost of borrowing for the government. A small fraction of it might be allocated to equity, and a smaller fraction of that might be allocated to startups, etc.
Setting aside the UBI goal, even if they weren't returning the money to the investment cycle, your funding scheme is difficult to implement. The importance of cash reserves varies from company to company:
1. Some have pretty much no reserves, and when the overnight market collapsed in 2008, their ability to make payroll was suddenly in question. Otherwise productive companies had operations jeopardized by their financial arrangement. A tax on cash reserves would create additional incentive to produce more risky companies.
2. Banks have huge liabilites and cash reserves in the form of deposits. They're even required to keep certain amounts of money in liquid cash reserves. Do you propose offsetting cash on hand with liabilities owed?
3. Apple actually took out a huge loan against overseas money to fund a dividend. Overseas money is currently not taxable, do you wish to change that? Do you even need to tax reserves if you do?
4. Using the same company for another example: Apple is reputed to finance their supplier's manufacturing facilities. Do you want non-Apple companies to make investments in their company, their supply chain, etc. they currently aren't making? One has to assume boards don't approve capital investments aren't profitable. If the choices are pay a taxable dividend, hold as highly taxable cash, or invest it at a slightly negative, we may see more unproductive investments.
Note that I'm not against UBI, but we have to think about how changes to tax law results in changes in behavior.