Econ Papers Daily / 期刊论文
撒哈拉以南非洲国家增长加速直接来源的另一种概念框架
AN ALTERNATIVE CONCEPTUAL FRAMEWORK OF THE PROXIMATE SOURCES OF GROWTH ACCELERATIONS IN SUB-SAHARAN AFRICAN COUNTRIES
摘要
Although policymakers generally regard physical capital accumulation as a key driver of economic development, numerous studies identify total factor productivity (TFP) as the main determinant of living standards. A recent application of the conventional growth-accounting framework to medium-run output-per-worker growth accelerations in sub-Saharan African (SSA) countries attributes 86.7% of growth to TFP and only 11.5% to physical capital accumulation. We argue that the conventional assumption of zero learning-by-doing effects may misrepresent growth accelerations. Alternatively, we develop a two-regime learning-by-doing model and calibrate it for SSA countries. Under this framework, physical capital accumulation becomes the dominant source of growth accelerations (58.9%) relative to TFP's contribution (39.6%). We further show that simply increasing the capital elasticity in the conventional model cannot capture these quality effects. Evidence from Ethiopia and complementary panel estimates for SSA countries support regime-dependent learning-by-doing effects and a substantially larger contribution of physical capital accumulation to growth accelerations.
中文摘要
尽管政策制定者通常将物质资本积累视为经济发展的关键驱动力，但大量研究认定全要素生产率（TFP）是生活水平的主要决定因素。近期将传统增长核算框架应用于撒哈拉以南非洲（SSA）国家中期人均产出增长加速的一项研究，将86.7%的增长归因于TFP，仅将11.5%归因于物质资本积累。我们认为，传统假设中干中学效应为零可能误判了增长加速。作为替代，我们构建了一个两状态干中学模型，并针对SSA国家进行了校准。在该框架下，物质资本积累成为增长加速的主要来源（58.9%），而TFP的贡献为39.6%。我们进一步表明，仅在传统模型中提高资本弹性无法捕捉这些质量效应。来自埃塞俄比亚的证据以及针对SSA国家的补充面板估计支持状态依赖的干中学效应，以及物质资本积累对增长加速的贡献显著更大。