The adjustment portion in equation (1) is the difference between net incomes reported under the two methods, while that in equation (2) is net income differential as a percentage of sales. Directions of adjustment in equation (1), which will be the same as that of the adjustment in equation (2), can indicate that net incomes under absorption costing of the companies studied are higher or lower than those which would have been under variable costing for most companies. Negative (positive) adjustments indicate that companies reported net incomes under absorption costing that are higher (lower) than those that would have been under variable costing.