Is military spending good for economic growth? According to some studies, the answer is affirmative. Military spending boosts business confidence, particularly in conflicting countries, which facilitates physical investment and economic growth. Others find that government spending on military hardware lowers macroeconomic growth as it crowds out social expenditures and investment in economically productive sectors. The lack of systematic evidence implies that policy decisions relating to military spending need not consider the associated economic costs and benefits. However, there are at least two methodological reasons for which past evidence remains contested.