Literature Review
The ideas that FDI led economic growth, business environment positively contribute to economic growth remains extremely controversial. This could be due to the use of different samples by different researchers, or due to the problem associated with the methodology used in each study or to the differences in the economy’s characteristics in each single country.
Theoretically, economic growth is a well-studied issue. The role of technological progress has been included in the production function as a determinant of the growth by [14] that is devoted a model of longrun growth to include the price-wage-interest reactions, interest-elastic savings schedule and allowed for the neutral technological change. Extend the Solow model to include the human capital accumulation through years of schooling in the production function [15] . Closely following the work of Solow, Lucas examined the interaction of physical and human capital accumulation on growth. The inclusion of the education human capital in the growth model continued in the work of [16-18] and expanded to include the health human capital in the production function as an important determinant of economic growth [19-21] . In-other side, there are two main theories in the impact of investment on growth which are the Modernization theory and the Dependency theory. The Modernization theory insists that the Third World is underdeveloped and remains in such a state because of its historical failure to industrialize and modernize with technology, the theory consider the lack of the finance as a one of the reasons associated with the failure of those countries. One of the solutions provided by this theory is the foreign direct investment which assumed to have positive impact on economic growth. The Dependency Theory however, is opposed to all the assessments and solutions offered by the Modernization Theory. The Dependency Theory argues that the plight of the Third Worlds as a result of the rapid economic growth and economic development in the First World countries. Thus, the theory believes-in the negative effects of the foreign direct investment on the economic growth .
Empirically, the impact of FDI on growth is subject to the level of existing business environment in the host country. For-instance, found that FDI by itself have a positive significant impact on growth but countries with well-developed financial market benefits more from FDI. The pervious finding has been confirmed by they resulted that the positive impact of FDI on economic growth kicks-in only after financial market development exceeds a threshold level, until then the benefits of FDI is non-existent. Moreover, FDI by itself can contribute positively to economic growth and its impact is not subject to a particular environment Moving-forward, the impact of FDI on growth has found to be insignificant in the short-run and the long run as well . A different view has been added to the previous results, which is that FDI have a negative impact on economic growth [, they justified their finding due to the technology-gap and poor business environment in the countries of interest. Moreover, [ found a bi-directional relationship between foreign direct investment and economic growth in 13 selected MENA countries.
The growth equation
Following the contribution of [14–20] and other economists in developing the new growth theory and to search for a set of variables for modeling the growth, a degree of convergence on the most empirical specification has occurred. The explanatory variables for economic growth in those studies are identified to include population, domestic investment, foreign investment, human capital and infrastructure stock. The growth model in this study is therefore:
Pooled mean group technique
According to Pesaran and Smith the traditional estimators such as fixed-effects, random-effects and generalized method of moments GMM can lead to inconsistent estimates in the long-run due to the slope heterogeneity bias. The PMG is introduced by Pesaran et al. to overcome this problem associated with those estimators. One advantage of the PMG is that it allows for the short-run dynamic specification to vary across countries, while the long-run coefficients are constrained to be the same.
The data
The study is using a panel of 39 Sub-Saharan Africa countries which divided into two groups of income levels, namely, 21 low income countries and 18 middle income countries in a period time from 1992 to 2012. The data used is obtained from World Development Indicators and African Union. The variables used in this study are real GDP, FDI as a percentage of GDP human capital proxies by secondary school enrollment, the infrastructure (IF) proxied by access to electricity as a percentage of population, gross capital formation (K) and total labor force (L)