Before the airline industry was deregulated, the Airline Pilots Association (ALPA) was generally regarded as one of the most successful unions in raising wages of its members; the International Ladies Garment Workers Union (ILGWU), on the other hand, had only limited success in raising wages. First, use the four lawd of derived demand to explain this difference. Second, after deregulation of the airline industry, over 40 new airlines began business. What was the likely effect on the elasticity of demand for airline pilots? Which law of derived demand does this involve?