Does Private Investment Granger-Cause Economic Growth in the Presence of Dependencies? Panel Evidence from SADC Countries

This study examines the Granger-causal relationship between private investment and economic growth, accounting for cross-sectional dependencies in a panel of SADC countries from 1990 to 2022. Using disaggregated data and advanced panel econometric methods, including quantile causality tests, we find evidence of bidirectional causality among growth, private investment, foreign direct investment, and domestic credit. However, this relationship is heterogeneous and varies across the conditional distribution of growth. Sensitivity analyses confirm that the results are robust but contingent on institutional factors such as governance and the level of development. The findings suggest that policymakers should adopt integrated strategies that combine investment promotion with institutional and financial development to maximize growth benefits.