As quantity demanded increases from Q1 to Q2 in Figure 4.15 the expenditure on all other goods decreases. (Point b is lower than point a.) This means,
As quantity demanded increases from Q1 to Q2 in Figure 4.15 the expenditure on all other goods decreases. (Point b is lower than point a.) This means, therefore, that the person’s total expenditure on X has correspondingly increased. What, then, can we say about the person’s price elasticity of demand for X between points a and b? What can we say about the price elasticity of demand between points b and c and points c and d?