P_{3}; P_{2}; P_{i} D Q_{1}*Q_{2}; Q_{3}*Q_{4}*Q_{s} Quantity Figure 3.4.1 At price P_{1} in Figure 3.4.1 the equilibrium quantity is Q_{2} the equilibrium quantity is Q_{4} there is a shortage in the amount of Q_{4} - Q_{2} there is a surplus in the amount of Q_{4} - Q_{2} there is a tendency for the price to fall