The Effect of Golden Ratio-Based Capital Structure on Firm's Financial Performance

This study aims to apply the golden ratio to the capital structure of non-financial institutions in France and the United Kingdom to find the effect of the golden ratio's deviation from the capital structure on financial performance. A golden ratio is an irrational number with an approximate value of 1.618. In this paper, the golden ratio was applied to develop the assumption that the firm should use debt at a percentage of 61.8% and equity at 38.2%, which deviates from the capital structure variables. The final study sample consisted of 150 non-financial institution firms from France and 200 from the U.K. between 2002 and 2021. In addition, the general method of movement (GMM) was chosen to estimate the effect of capital structure variables deviating from the golden ratio on firms' financial performance. The study results show that when a firm uses equity at a percentage of 38.2% in its capital structure, it can have a positive and significant impact on its financial performance in both France and the U.K. However, the results show that the debt-to-equity ratio deviated from the golden ratio and had a negative and statistically significant effect on both countries' TOBQ, EPS, ROA, and ROE. Moreover, the firms' adoption of IFRS can positively and significantly impact financial performance in France and the UK. Generally, managers in France are encouraged to use 38.2% equity and 61.8% debt in their capital structure. However, managers in the U.K. should apply equity of 38.2% and debt of 61.8%, depending on the performance measurement demanded.