Replication Data for: Bread Before Guns or Butter: Introducing Surplus Domestic Product

Scholars systematically mismeasure power resources and military burdens by using gross domestic product (GDP) as a proxy for the income states can devote to arming. The core problem is that GDP confounds two conceptually distinct forms of income into one additive indicator. Subsistence income represents resources needed to provide the “bread” necessary to cover the basic subsistence needs of the population. Surplus income represents the remaining resources that could be allocated to “guns” or “butter.” Our new measure of surplus domestic product (SDP) corrects for this measurement error by decomposing subsistence income and surplus income from total GDP. Validation exercises demonstrate that SDP outperforms GDP at measuring the distribution of power resources. Though theoretically we expect states’ decisions to arm are influenced by the distribution of power; empirical models using GDP find mixed support for this expectation. Strikingly, using SDP reveals strong support for this proposition.

学界系统性地错误衡量了权力资源与军事负担，将国内生产总值（gross domestic product，GDP）作为国家可投入军备的收入代理变量。核心问题在于，GDP将两种概念上截然不同的收入形式混同为单一加总指标：生存性收入是指用于满足民众基本生存需求的"面包"类资源，剩余收入则是可被分配至"枪炮"（军备开支）或"黄油"（民生保障）的剩余资源。我们提出的新型国内剩余产值（surplus domestic product，SDP）测算方法，通过将总GDP拆解为生存性收入与剩余收入，修正了这一测算误差。验证实验表明，在衡量权力资源分布方面，SDP的表现优于GDP。尽管理论层面我们预期国家的军备决策会受到权力分布的影响，但使用GDP的实证模型仅能得到混杂不一的验证结果。值得注意的是，改用SDP进行分析则能为这一理论命题提供强有力的实证支撑。