First, the paper gives a critical appraisal of recently proposed quality adjustments of the ratio of private credit to the gross domestic product (GDP) as a proxy for finance in empirical tests of the finance-growth nexus and cautions against such heuristic measures. Second, in response to the unidimensional feature of conventionally applied proxies for finance, the paper constructs a variable for financial development (FD metric) that measures the relative distance of a financial system from its best attainable performance in terms of depth, access, efficiency, and stability. The measurement is grounded in the principles of data envelopment analysis for ratio data and is built on structural indicators available in the Global Financial Development Database by the World Bank. Using annual data for 157 countries over the period 1993–2020, the paper then explores the finance-growth nexus using several financial metrics in panel-data regression models and considering nonlinearity in both a parametric and semiparametric manner. Economic growth is found to react negatively to finance, whereas this detrimental effect strengthens beyond a certain level of financial depth. In contrast, the access, efficiency, and stability of the financial sector are less important for growth. Hence, the findings lend weight to an economic policy focused primarily on a minimal size of the financial sector that permits its smooth operations, without the need to ensure that the financial sector performs qualitatively at its best.

中文翻译：

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金融深度与更全面的金融发展指标在金融与增长关系测试中的比较

首先，本文对最近提出的私人信贷与国内生产总值（GDP）比率的质量调整作为金融与增长关系实证检验中金融的替代指标进行了批判性评估，并警告不要采取此类启发式措施。其次，针对传统金融替代指标的一维特征，本文构建了金融发展变量（FD指标），衡量金融体系在深度、准入、效率、和稳定性。该衡量标准以比率数据的数据包络分析原则为基础，并以世界银行全球金融发展数据库中提供的结构指标为基础。本文利用 1993 年至 2020 年期间 157 个国家的年度数据，利用面板数据回归模型中的多个金融指标，并以参数和半参数的方式考虑非线性，探讨了金融与增长的关系。研究发现，经济增长会对金融产生负面影响，而这种有害影响在金融深度超过一定水平后就会增强。相比之下，金融部门的准入、效率和稳定性对于增长来说不太重要。因此，研究结果支持主要关注金融部门最小规模的经济政策，以使其平稳运营，而无需确保金融部门在质量上发挥最佳水平。