Over the Top: U.K. World War I Finance and Its Aftermath

We argue that the fiscal policies adopted early in World War I by the U.K. were responsible for its poor economic performance during the interwar period. In September 1915, the U.K. embarked on a set of non-tax-smoothing policies collectively known as the McKenna rule. The key dictum of the McKenna rule was to raise tax rates on labor and capital income in response to contemporaneous movements in government spending. The greater reliance on income taxation produced distortions in household and firm decision making that have not previously been studied. We construct and calibrate a real business cycle model to assess quantitatively the impact of the McKenna rule. The model generates paths for aggregate variables that resembles actual U.K. economic activity from 1916 onward