Nonlinear effects of public debt on economic growth in Nigeria

The COVID-19 pandemic induced governments all over the world to momentarily accumulate higher levels of public debt in order to invest in deficit spending and social protection programs to tackle the anticipated economic slump. The Nigerian government has borrowed heavily from domestic and foreign sources in order to resolve the growing budget deficits and return the economy to a sustainable growth trajectory. Previous studies frequently made the incorrect assumption that the relationship between public debt and growth is linear and symmetric, leading to empirical results that is frequently disputed and imprecise. This study's main objective is to examine the asymmetric impact of public debt on economic growth in Nigeria from 1980 to 2020 using the Nonlinear Autoregressive Distributed Lag method. Empirical evidence indicated that external debt have a significant positive and symmetric impact on economic growth in the long and short run, while debt service payment supporting the debt overhang hypothesis activated a symmetric effect that stifle growth. Domestic debt retarded growth asymmetrically in the short term and linearly over the long term. Foreign reserve holding, on the other hand, had an asymmetric long-run influence and a symmetric short-run impact on growth motivation. To mitigate the negative effects of unsustainable public debt, the study advocated for fiscal reforms that effectively reduce deficit financing to keep the level of government debt low and be able to respond robustly to an economic shock, improve domestic revenue generation and infrastructure spending, and strengthen governance practices and institutions.