Innovation and pragmatism in tax design: Excess Profits Duty in the UK during the First World War

In this article, we examine the design and administration of Excess Profits Duty (EPD), introduced in the UK in 1915. This represented a significant innovation as the country's first comprehensive attempt to tax .excessive. business profits. EPD was a complex tax which had two objectives: to generate additional revenues to help fund dramatically increased wartime government expenditure and to curb .profiteering.. Although criticised on numerous grounds, we argue that the tax was surprisingly successful. For all its defects, it generated very substantial revenues, and its design and administration proved flexible and robust in coping with the uncertainties of war.