In a competitive market, the market demand is QS1U1P1dS1S1P0 = 60 – 6P and the market supply is QS1U1P1sS1S1P0 = 4P. A price ceiling of $3 will result in a shortage of 30 units. shortage of 15 units. surplus of 30 units. surplus of 12 units. See Answer shortage of 30 units.