Impact of Public and Private Investment on Economic Growth in Nigeria

The contention in the literature is the relative contribution of private and public investment on economic growth and whether the relationship is linear or non-linear. In addition, there is the issue of whether the impact of investment on economic growth changes depending on public and private investment Purpose. The study examines the relationship between investment (public and private) and economic growth in Nigeria over the period 1970-2016. Design/Methodology/Approach. The study employs Markov regime-switching approach developed by Hamilton (1989, 1990). Specifically, a multivariate dynamic Markov-switching model is estimated using maximum likelihood estimation techniques. The study employs annual time-series sourced from Central Bank of Nigeria, Statistical Bulletin and World Bank, World Development Indicator. Findings/Implications. The results show that the relationship between investment and economic growth is non-linear. Also, both public and private investments have a significant positive impact on economic growth. However, private investment contributes more to economic growth than public investment during the period of expansion. The reverse is the case during the period of contraction. The results support the basic neoclassical framework, with emphasis on savings and investment for analyzing long-term growth performance. Also, it is crucial to make a distinction between the impact of investment (public and private) on growth in two stages of growth. Originality. Government needs to be innovative by spending more during period of slump as more public investment will be required to pump prime the economy for increased private investment.