The efficient frontier has a concave shape (i.e. a bulging shape) because: There is a quadratic relationship between higher quality and efficiency Cost of providing quality increases in the level of quality Quality is free at lower levels of quality Greater levels of efficiency come at a steep cost but only for high-end segments If the willingness to pay of a customer for an automobile is $18000, and the cost to produce that automobile is $14000, the consumer surplus is: Less that $4000 $4000 More than $4000 Cannot be determined with data provided