Increase turnover
-inflation will produce some gains in turnover ratios. This could be due to the LIFO inventory valuation models or due to sales rising more rapidly than fixed assets. However these gains wont result in substantial improvements in the return on equity capital

Cheaper leverage
-this is unlikely to happen
- high rates of inflation generally cause borrowing to become dearer, not cheaper

More leverage
- in an inflationary environment the cost of leverage increases. Thus offsetting the usual benefits of leverage

Lowering corporate incomes taxes
-this is unlikely to happen, thus there is no need to discuss this further

Wider Operating Margin on Sales 
-labor, raw materials, energy and various non income tax costs tend to increase with inflation. This thus depresses margins