A capital levy is a tax on capital rather than income, collected once, rather than repeatedly (regular collection would make it a wealth tax). For example, a capital levy of 30% will see an individual or business with a net worth of $100,000 pay a one-off sum of $30,000, regardless of income. Capital levies are considered difficult for a government to implement. Some economists argue that capital levies are a disincentive to savings and investment, and cause capital flight, but others argue that in theory this need not be the case. The latter view was popular in the World Wars; in the 2010s, it has also gained some acceptance as more heavily indebted nations struggle to raise revenues. Examples of capital levies Ancient democracies In ancient Athens during its democracy, there was a form of capital levy known as a liturgy (). The liturgy might anything from financing a public play to supplying and manning a trireme for the navy. An Athenian could volunteer for such a levy, but if no-one volunteered, a wealthy person meeting the eligibility requirements would be ordered to supply it. They could escape by nominating someone wealthier to take over the duty; if the nominated person disputed this, the nominator could take the liturgy, or offer to exchange property with their nominee (antidosis). If the nominee refused, the matter went to court, and the liturgy was assigned whoever the court case determined to be wealthier. Athenians often concealed their wealth to escape taxation, and sycophants who discovered concealed wealth might use it as blackmail material. Antidosis helped the state identify the wealthiest people, and kept the rich suspicious of one another. Athens also had a wealth tax called eisphora (see symmoria), and for this purpose the city required each rich person give an estimate of his fortune (τίμημα). These self-assessments were not very accurate. The liturgy has not been much studied by economists. 20th century During both World Wars, capital levies were introduced, with the generally-stated aim of distributing the sacrifices required by the war more evenly. This had a significant effect on both income and wealth distributions, lasting decades into the post-war period. Such policies were commonly referred to as the "conscription of wealth". The Economist, a British publication, opposed capital levies, but supported "direct taxation heavy enough to amount to rationing of citizens' incomes"; similarly, the American economist Oliver Mitchell Wentworth Sprague, in