the fiscal and monetary methods that are used in meeting the costs of war, including taxation, compulsory loans, voluntary domestic loans, foreign loans, and the creation of money. War finance is a branch of defense economics (q.v.).

Government efforts to finance major wars have frequently led to major changes in the tax (taxation) system. In the United States, for example, the importance of the personal income tax as a revenue source increased significantly during World War II, when higher rates, lower exemptions, and a deduction-at-source system of collection were introduced. Great Britain and many other belligerents in World War II resorted to general sales taxes.

Compulsory loans have been used as an alternative to taxation, but they have usually been perceived as taxes by the public. Voluntary loans, in which money is raised by selling government bonds, are of two types: those financed by the public from its savings and those financed by bankers and others from credit created by expansion of the monetary supply. The first type of loan is generally anti-inflationary in its effects because it eliminates excess purchasing power. The second type of loan, under wartime conditions, is likely to be as inflationary as would be the printing of the same amount of new paper currency.

A popular fallacy about war finance is that government borrowing transfers the war costs to future generations. The real costs in goods and services underlying the monetary costs, however, are paid by the war generation when the government uses the real resources for war, bidding them away from other uses.

The most dangerous form of war finance is the printing of new paper money, resorted to when no more taxes can be collected and the government's credit has broken down. Usually the printing is not done by the government directly but by the central bank, which then lends the printed money to the government through purchases of bonds.

Major wars are usually financed to some extent by inflationary (inflation) measures. Inflation distributes the burden of war costs in an arbitrary manner, penalizing persons with fixed incomes. After a certain point, inflation may even lower production by placing a premium on the hoarding of raw materials and durable goods, as well as the holding of real estate and other fixed assets, thus shifting resources from productive to nonproductive uses.