BP Plc has ordinary shares amounting to £1,500,000 and 12% debentures of £300,000. Royal Dutch Shell has ordinary shares worth €1,200,000 and 10% debentures of €400,000. ExxonMobil's capital structure includes $1,000,000 in ordinary shares and $500,000 in 8% debentures.

In 2012, the return on capital employed for each firm was 19%, and in 2013 it was 8%. The corporation tax rate in both years was 46%, and debenture interest is deductible for tax purposes.

(a) Determine the percentage return on the shareholders' capital for each company for 2012 and 2013. Assume all profits are distributed. (b) Analyze the advantages and risks associated with high financial leverage for these companies.