Final answer:
The example demonstrates a trade-off between economies of scale and providing a wide assortment of products, reflecting why both discrepancies of quantity and assortment occur in the marketplace.
Step-by-step explanation:
The situation described in the student's question focuses on the concept of economies of scale within the publishing industry, where it is more cost-effective to produce large quantities. This efficiency in production, however, leads to a discrepancy in quantity as bookstores only order a few copies due to their customers preferring a variety from which to choose. This is a clear demonstration of the trade-offs between achieving economies of scale (efficiency) and providing a wide assortment of products. This duality of concerns represents why both discrepancies of quantity and discrepancies of assortment occur.
Large-scale production indeed lowers the cost per unit, as seen with companies like Amazon, which, utilizing massive warehouses and streamlined distribution systems, can offer a wide variety of products cost-effectively. The discussion reflects the economic principles where market-oriented economies face the challenge of determining the right amount of variety, taking into account the societal worth of product differentiation against the benefits of mass production.