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H₀: Government spending on infrastructure has no significant impact on Nigeria‘s economic growth during the pre SAP, SAP and post SAP periods

H1: Government spending on infrastructure has significant impact on Nigeria‘s economic growth during the pre SAP, SAP and post SAP periods

Hypothesis 2

H0: There were no structural breaks experienced during the pre SAP, SAP and post SAP periods for economic growth and aggregate spending in Nigeria.

Hi: There were structural breaks experienced during the pre SAP, SAP and post SAP periods for economic growth and aggregate spending in Nigeria.

Hypothesis 3

H0: There is no causal link between government spending on infrastructure and Nigeria‘s economic growth.

Hi: There is causal link between government spending on infrastructure and Nigeria‘s economic growth.

Hypothesis 1

This is the proposition that government spending for infrastructure has no significant impact on economic growth in Nigeria during the pre – SAP, SAP and post SAP periods.

From our ARDL short run analysis during the pre-SAP period, we observed that the variables employed to examine the impact of government spending for infrastructure on economic growth (transport sector, communication sector, health sector, education sector and utilities), with the exception of the health sector, were all significant as the probabilities of their absolute t-statistics were less than the critical t_0.05 value. This means that the sectors included in the model with the exception of the health sector, have positively significant impact on economic growth in Nigeria during the pre-SAP period.

From the ARDL short run analysis during the SAP period, we observed that the variables employed to examine the impact of government spending for infrastructure on economic growth (transport sector, communication sector, health sector, education sector and utilities), with the exception of the health sector, were all positively significant as the probabilities of their absolute t-statistics were less than the critical t0.05 value. This means that the sectors included in the model with the exception of the health sector, have significant impact on economic growth in Nigeria during the SAP period.

We also observed from the ARDL short run analysis during the post-SAP period that the variables employed to examine the impact of government spending for infrastructure on economic growth (transport sector, communication sector, health sector, education sector and utilities), were all insignificant as the probabilities of their absolute t-statistics were greater than the critical t0.05 value. This means that the sectors included in the model have no significant impact on economic growth in Nigeria during the post-SAP period.

Lastly we also observed from the ARDL short run analysis for the entire period that the variables employed to examine the impact of government spending for infrastructure on economic growth

(transport sector, communication sector, health sector, education sector and utilities), were all insignificant as the probabilities of their absolute t-statistics were greater than the critical t0.05

value. This means that the sectors included in the model have no significant impact on economic growth in Nigeria during the entire period.

Judging from the result above especially that of the post-SAP and the entire periods, with the health and communication sector outcome in the pre-SAP and SAP periods, this leads to the acceptance of the proposition and the rejection of the alternative hypothesis making us to conclude that government spending for infrastructure have no significant impact on economic growth in Nigeria during the pre – SAP, SAP and post SAP periods.

Hypothesis 2

This is the proposition that there were no structural breaks experienced during the pre SAP, SAP and post SAP periods for economic growth and aggregate spending in Nigeria. From the Zivot-Andrews test analysis, we observed there were structural breaks both highest peaks and lowest peaks experienced during the pre SAP, SAP and post SAP periods for economic growth and aggregate spending in Nigeria. This leads to the acceptance of the alternative hypothesis making us to conclude that there were no structural breaks experienced during the pre SAP, SAP and post SAP periods for economic growth and aggregate spending in Nigeria.

Hypothesis 3

This is the proposition that there is no causal link between government spending for infrastructure and economic growth in Nigeria for the entire period. From our granger-causality analysis, we observed closely that there exists no causal link between the growth rate of the government spending for infrastructure in the sectors included in the model (transport, communication, health, education and utility sectors) and economic growth rate in Nigeria. We therefore accept the null hypothesis making us conclude that the there is no causal link between government spending on infrastructure and Nigeria‘s economic growth.