If consumption is measured by the value of income obtained, this diagram can be used to show a variety of interesting effects. This is because the absolute value of the slope of the budget constraint is the wage rate. The point of optimisation (point A) reflects the equivalency between the wage rate and the marginal rate of substitution of leisure for income (the absolute value of the slope of the indifference curve). Because the marginal rate of substitution of leisure for income is also the ratio of the marginal utility of leisure (MUL) to the marginal utility of income (MUY), one can conclude: