Industrial Mobilization for War: Conversion Distance, State-Business Relations, and Wartime Production

Why do some states generate military power from economic resources more effectively than others? Standard answers focused on regime type, wealth, or aggregate resources cannot explain why countries matched on these characteristics often diverge sharply in mobilization outcomes. I argue that the effectiveness of industrial mobilization depends on two characteristics: conversion distance—the gap between peacetime economic capabilities and wartime production needs—and whether state-business relations enable effective state intervention in the economy. When conversion distance is short, increasing military production is faster and less costly. When state-business relations combine insulation from parochial interests, access to firm-level information, and authority to reallocate resources and discipline private actors, states can develop and administer sound mobilization policy. An original Military Production Dataset allows measurement of outcomes and supports case selection. I then evaluate the argument with cross- and intra-case evidence drawn from a most-similar comparison of Japan and Italy in World War II. Despite comparable economic resources, regime type, military strategies, and conflict expectations, Japan produced more than four-and-a-half times more equipment in priority sectors between 1940 and 1943. The argument refines materialist and institutional accounts of power generation with implications for the measurement of the balance of power and the duration and outcomes of war.