Concentration of Ownership and Major Customer on Tax Avoidance with an Emphasis on the Role of Corporate Governance

Tax authorities continue to face unresolved corporate tax avoidance issues. Changes in tax systems have led to corporate tax avoidance opportunities to the benefit of shareholders. The purpose of this study is to examine the relationship between concentration of ownership and major customer with tax avoidance and corporate governance criteria (board size, board independence, CEO duality, audit committee size, audit committee independence, financial expertise of audit committee members) as moderating factors are considered in this relationship. The statistical population of the study consisted of the companies listed in Tehran Stock Exchange during the period 2012-2016. Samples were systematically eliminated and 82 companies were studied as sample. The TOPSIS method has been used to rank companies based on corporate governance criteria. Data analysis and hypothesis testing were performed using multivariate regression and panel data. The results of the research hypothesis test indicate that there is a positive and significant relationship between ownership concentration and tax avoidance, and corporate governance undermines this connection. There is also a positive and significant relationship between major customer concentration and tax avoidance, and corporate governance has no significant effect on this relationship.