This study empirically examined the relationship between corporate governance mechanisms and tax sheltering of publicly traded tax aggressive companies in Nigeria. To determine the relationship between corporate governance mechanisms and tax sheltering, corporate governance mechanisms were measured with CEO share ownership, directors' remuneration, board independence and board diligence, while tax sheltering was proxy using effective tax rate. The hypotheses formulated to guide the study and the statistical testing of the parameter estimates were worked out using the OLS regression model using STATA V.15. The ex post facto design was adopted and the data for the study was sourced from the published annual financial reports of all tax aggressive companies classified under ICT Sector, Health Care Sector and Oil & Gas Sector of the Nigerian Exchange Limited (NGL) covering from 2013-2021. The results indicate that corporate governance mechanisms having significant and positive association with tax sheltering of listed tax aggressive companies in the country. The study concludes that corporate governance mechanisms ensure tax sheltering for tax aggressive companies. The study however suggests that firms’ board should consider the percentage and proportion of CEO’s share ownership concentration, pay higher remuneration to the board members, increasing the number of independent directors in their board and also consider in composition of the board of directors, their level of expertness, expertise, intelligence and proficiency as these led to tax sheltering among the quoted firms in Nigeria.

This study was carried out on impact of corporate diversification on the sustainability of healthcare companies in Nigeria. To determine the relationship between corporate diversification and organizational sustainability, corporate diversification was measured using geographic diversification (GEODIV), operational diversification (OPDIV), and product diversification (PRODIV), while sustainability, on the other hand, was measured using Kinder Lydenberg Domini (KLD) rating system on social-environmental performance. Ex post facto design was used and the data were collected from the annual reports and accounts of the listed healthcare companies in Nigeria for the period up to 2016-2020. The OLS model was used in the data analysis and the results of the study show that geographic diversification, operational diversification & product diversification have positive and a significant effect on corporate sustainability at a significant level of 1%. Therefore, the study concluded that corporate diversification ensures organizational sustainability in Nigeria. Hence, the study recommended that business organizations should engage in diversification (GEODIV, OPDIV & PRODIV) as this ensures organizational sustainability. Hence, proper management of diversification decisions is required, as over-diversification could lead to a deterioration in the company's financial performance.

This study empirically investigated the relationship which exists between tax aggressiveness moderated by firm size and sustainability of oil and gas firms in Nigeria. In order to determine the relationship between tax aggressiveness and corporate sustainability, tax aggressiveness was measured using effective tax rate while corporate sustainability on the other hand was proxy using social-environmental performance. The formulated hypotheses to guide the investigation and the statistical test of parameter estimates was conducted using OLS regression model operated with STATA V.15. Ex Post Facto design was adopted and data for the study were obtained from the published annual reports and accounts of listed oil & gas firms on Nigerian Exchange Group (NGX) spanning from 2013-2021. The findings of the study generally indicate that tax aggressiveness has significant and positive relationship with sustainability of quoted firms in Nigeria at 1% significant level. In the same vein, it was noted that firm size moderates the relationship between tax aggressiveness and corporate sustainability at 5% level of significance. Thus, the study concludes that tax aggressiveness ensures sustainability of firms in Nigeria. The study however suggests the need for corporate organizations to engage the services of tax consultants to assist them to organize the firm’s financial dealings in such a way t hat t he firm suffers a minimum tax liability.