Final answer:
The memo states that two-sided platforms, network effects, and scope economies are reasons why large tech firms charge consumers low prices. Increasing marginal costs is not a reason for charging low prices.
Step-by-step explanation:
The memo discusses reasons why many large tech firms charge consumers low prices compared to large firms and monopolies of the past. These reasons include two-sided platforms or markets, network effects, and scope economies. Two-sided platforms refer to platforms that bring together two distinct groups, such as users and advertisers, and generate value by facilitating interactions between them. Network effects occur when the value of a product or service increases with the number of users or participants. Scope economies refer to cost savings that result from producing a wider range of products or services.
On the other hand, increasing marginal costs is not a reason for charging low prices. Increasing marginal costs occur when the cost of producing an additional unit of a product or service increases as the quantity produced increases.