Threshold Effect of Public Investment on Economic Growth in The Democratic Republic of Congo: Regime Change Approach

This study analyzes the threshold effect of public investment on economic growth in the Democratic Republic of Congo (DRC), over the period from 1985 to 2022. Based on the threshold regression model of Hansen (1999, 2000) and the work of Barro (1990) and Aschauer (1989), it aims to identify a critical level of public investment beyond which its impact on economic growth changes in nature. The results show that when the public investment ratio is below 2.12%, it has a negative effect on growth, unlike private investment, which remains favorable. For a ratio between 2.12 and 4.1, both public and private investment stimulate growth. Above 4.1%, public investment continues to have a positive effect, while private investment loses statistical significance. The study highlights the importance of strategic management of public resources, in line with Barro's (1991) recommendations, to maximize the impact of investments on growth. Poor allocation of public funds can significantly reduce their economic return. Thus, strengthening the institutional framework and governance appears essential to improve the effectiveness of public investments and promote sustained and inclusive longterm growth in the DRC.