This study tests the validity of Wagner's hypothesis on public expenditure and output growth in Nigeria from 1970 -2016 using annual time series data. Phillips Perron unit root test (PP), Johansen cointegration test, Vector Error Correction Model (VECM) and pair wise Granger causality econometric analytical methods were employed. The stationary property of the research variables was confirmed and other tests in the study revealed a unidirectional causation from government expenditure to economic growth in the country. The finding of the study therefore invalidates the applicability of Wagner's hypothesis in Nigeria within the study period. The study recommends the need for appropriate policies on effective utilization of public fund knowing that it has positive effect on the level of economic growth in the country.

The paper examined the nexus existing among carbon emissions, mortality rate and economic growth in Nigeria using the annual time series data spanning from 1981 to 2019 by employing the Autoregressive Distributed Lags (ARDL) Model application to cointegration and Error Correction Model techniques. Unit root test was conducted on all the variables of interest in the study. The study finds evidence of a long-run relationship existing among Carbon emissions, mortality rate, education expenditures and economic growth in Nigeria. The findings of this study has implications for energy policy as policy makers and economic planners need to formulate and implement policies aimed at conserving energy use, improving energy efficiency and designing energy demand management in such a way that the Nigerian government should embark on the alternative use of energy that generates less emission of carbon dioxide as this will unequivocally help Nigeria to achieve the sustainable development goals of good health and well-being alongside with affordable, reliable and sustainable use of energy for all. In addition, there is the pressing need for the government and other relevant stakeholders to formulate and enforce policies aimed at curbing the emission of carbon into the environment, given its hazardous, debilitating and deleterious consequences on human health status and the environment as this is believed to go a long way in reducing mortality rate that might be associated with depletion in ozone layer causing exposure to high heat stress, ultraviolet radiation and air pollution in Nigeria.