When a monopolist practices price discrimination as opposed to setting a single price,the monopolist increases its profits by capturing consumer surplus.

When a monopolist practices price discrimination, they can charge different prices to different groups of consumers based on their willingness to pay. This allows the monopolist to capture more of the consumer surplus and increase their profits. By charging a higher price to those who are willing to pay more and a lower price to those who are less willing, the monopolist is able to extract more overall value from the market.