When consumers purchase cell phones, they also often purchase a protective case to take care of the cell phone. As the price of a cell phone falls, the demand for a protective case shifts to the right. This means cell phones and a protective case are .

Many potential buyers value high-quality used cars at the full-information market price of € p1 and lemons at € p2. a limited number of potential sellers value high-quality cars at € v1 ≤ p1 and lemons at € v2 ≤ p2. everyone is risk neutral. the share of lemons among all the used cars that might be potentially sold is € θ . suppose that the buyers incur a transaction cost of $200 to purchase a car. this transaction cost is the value of their time to find a car. what is the equilibrium? is it possible that no cars are sold