Public investment and private sector performance in Nigeria

Purpose - This study explores the asymmetric linkage between public investment and private sector performance in Nigeria. This is due to the presence of nonlinear structures in the behavior of domestic investment series with evidences of structural time breaks, which fall within periods of global financial crises and oil shocks. Design/methodology/approach - Main data on gross capital formation, gross fixed capital formation, domestic credit to private sector, domestic credit to private sector by banks are used for the study span through 1986 to 2017. Evidence of asymmetry spurs the study to adopt the nonlinear autoregressive distributed lag, asymmetric generalized impulse response and variance decomposition and asymmetric granger causality techniques. Findings - It is shown that positive (negative) investment shocks exhibit a non-negligible and substantial stimulating (dampening) influence on the long-run performance of private sector in the economy. However, there is evidence that negative investment shocks portend a positive influence on the performance of private sector in the short run. This suggests that negative shocks to investment may not dampen the effectiveness of private sector in the short run, and this thus brings to bear the debate on the tenability of public investment as a potent counter cyclical tool in enhancing short-run private sector growth. The nonlinear granger causality also shows a unidirectional nonlinear causality from public investment to private sector performance. However, there is no evidence of bidirectional nonlinear causality. Originality/value - This study provides quantitative evidence that Nigeria still depends exclusively on public investment, and as an oil-based rentier economy its economic diversification drive still remains bleak.