Inflation, croissance économique et pouvoir d'achat en RDC : une analyse économétrique à l'aide d'un modèle VAR[inflation, economic growth and purchasing power in the DRC : an econometric analysis using a VAR model]

Inflation remains one of the most critical macroeconomic challenges facing the Democratic Republic of the Congo (DRC) due to its adverse effects on household purchasing power and economic stability. This study investigates the impact of inflation on purchasing power in the DRC over the period 2005–2023 using a Vector AutoRegressive (VAR) model. The analysis is based on three key macroeconomic variables: the inflation rate, the real interest rate used as a proxy for purchasing power, and the economic growth rate. Descriptive statistical analysis was first conducted, followed by Augmented Dickey-Fuller (ADF) unit root tests to assess the stationarity properties of the series. Subsequently, a VAR model was estimated to examine the dynamic interactions among the variables. The analysis was further complemented by impulse response functions and forecast error variance decomposition. The empirical findings indicate that inflationary shocks exert a significant negative effect on purchasing power by reducing households’ real income. The impulse response analysis reveals that the adverse effects of inflation persist over several periods before gradually diminishing. Moreover, variance decomposition results show that economic growth plays a substantial role in explaining long-term fluctuations in purchasing power. These findings are consistent with the monetarist theory, which identifies inflation as a major determinant of purchasing power erosion. The study therefore recommends strengthening macroeconomic stabilization policies, enhancing inflation control mechanisms, promoting domestic production, and fostering inclusive and sustainable economic growth in order to improve living standards and support long-term economic welfare in the Democratic Republic of the Congo.