1. First-degree price discrimination. This is sometimes referred to as perfect price discrimination, since all the consumer surplus is transferred to the producer. For this to be possible the producer must have complete knowledge of its demand curve, in terms of knowing the highest price that each customer is prepared to pay for each unit, and be able to sell the product accordingly This situation is extremely rare, but an example is an auction market, like the Treasury Bill market. Figure 10.2 illustrates the situation. It is assumed in this case that marginal costs are constant, for simplicity. The whole consumer surplus, GCP3, becomes revenue and profit for the producer.