A capital levy is a tax on capital rather than income, and is collected once rather than annually. For example, a capital levy of 30% will see an individual or business with a net worth of $100,000 pay $30,000 in tax, regardless of income. It is considered difficult for a government to implement, as the confiscatory nature of taxation is more apparent than with income tax. Thus once such a levy is enacted, capital flight is likely to ensue.
Some economists argue that capital levies are a disincentive to savings and investment, though others argue that in theory this need not be the case.