It is rather a norm for researchers to directly use the log difference of an asset price to compute returns. Just like using ln(X + 1) to avoid taking the natural logarithm of zero(s). However, this log returns is but a conditional approximation of the actual returns. Nonetheless, can log difference approximations and the ln(X + 1) common practices produce BLUE estimates? Using the log return as an example, this study discusses the approximation nature and conditions for using the log difference approximation both for the interest regressor and control variables. These conditions are; that both the sample average and variance of the original series tend to zero. When these conditions are not met, the log difference approximation is, in fact, not a good approximation and biases OLS causal estimators. When the conditions are met, it produces unbiased, consistent but less efficient estimators. Thereby making the estimates less precise and less accurate. Nonetheless, this is true for a log dif ferenced interest regressor(s) and control variables, when it correlates with the interest variable(s) and explains, in part, the dependent variable, even in large samples. Similarly, the common use of ln(X +1) biases the esti mation of the true causal effect, even the intercept term, except when X tends to infinity. A robust solution of using non-zero subsamples, against ln(X + 1), produces unbiased and consistent estimators for the true causal effects under the causal assumptions. These biasedness, inconsistencies, and inefficiencies do not disappear in large samples. Finally, both ex-ante and ex-post test statistics are discussed, however, the ex-post estimation test statistic is recommended to confirm both the choice of using log difference approximation and that of using ln(X + 1), in an empirical data causal regression analysis. Ideally, researchers should ensure the conditions for using the log difference approximation are met. Otherwise, these approximations and practices produce biased, inconsistent, and inefficient results, even in large samples, leading to misinformed policy implications.

Should Africa rather delay investments in renewable energy given their trivial contributions to global greenhouse gas emissions? This is strongly discouraged given the existing benefits of increased renewable energy investments in an African economy. Nigeria, the leading African economy is adopted as a representative to illustrate the prospects of improved (renewable) energy security in Africa. This study develops a dynamic recursive general equilibrium model to evaluate the prospects of renewable energy investment paths for Africa towards improving its energy security levels. Unlike other competing models, this model allows businesses to dynamically substitute between intermediate renewable energy and fossil fuel products, thus, taking active steps towards achieving a green economy. The results show that present economic welfare will be sacrificed for future welfare benefits and improved energy security. This confirms the transitioning of an economy from a lower steady state to a higher steady state path as postulated by the Solow model. However, a sustained gradual investment in the renewable energy sector yields the least welfare loss as the economy transitions through its energy security path. The one-off policy design produces relatively higher results in the immediate future while the sustained gradual incremental path smoothens these results into the far future. The results confirm that Africa’s demand for renewable energies substantially outweighs its supply, thereby suggesting a potential and non-trivial market for renewable energies, nonetheless. Results-based policies that are geared towards improving energy security are formulated for the African economies.

The rising spate of inflation in Nigeria has become worrisome in recent years, considering its implications on the quest for tourism development in the country. This study, therefore, empirically evaluates the effect of inflation on the Nigerian tourism industry. Two tourism indicators (tourism arrivals and tourism receipt) are employed in this study for robustness and quarterly data on relevant variables for the period between 1995Q1 and 2020Q4 were analysed using different econometric approaches. The results of all the estimation methods unanimously revealed a trade-off between inflation and the two tourism indicators, signalling that inflation dissuades international tourist arrival and lower tourism revenue in Nigeria. Hence, the Nigerian monetary authority must ensure price stability by keeping the inflation rate at a desirable level in a bid to foster tourism development in the country.

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Authors: Isiaka Raifu Akande and Joshua Adeyemi Afolabi

This study simulates the effect of fuel subsidy removal on different categories of inflation in Nigeria using the novel dynamic simulated autoregressive distributed lag framework. Findings revealed heterogeneity in the inflationary effect of an increase in premium motor spirit price across locations, and that the recent fuel subsidy removal in Nigeria will have long-lasting negative inflationary effects.

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Authors: Isiaka Akande Raifu, Joshua Adeyemi Afolabi
 

This study examines the effect of access to clean fuel and technology on health outcomes, drawing a comparison between Africa and Asia over the period 2000–2021. Using Generalised Least Squares, our findings revealed that access to clean fuel and technology improves health outcomes in both regions, suggesting that having access to clean fuel and technology is indispensable to improving health outcomes in Africa and Asia. Thus, governments in the two regions should prioritise and invest in technology that provides access to clean energy.

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Authors: Isiaka Raifu Akande and Nantap Rejoice Ditep