Final answer:
In a merchandising business, the buying or purchasing department typically initiates purchases, sourcing products to meet consumer expectations influenced by historical shifts in consumerism and the rise of department stores and mail-order houses.
Step-by-step explanation:
The function or department that typically initiates a purchase in a merchandising business is the buying or purchasing department. In a modern retail context, this department is responsible for selecting and procuring products that will be sold in the store or through the business's various channels. The advent of department stores and mail-order houses like Sears illustrated a shift towards consumerism - where consumer demands in merchandise and a variety of goods became more prevalent. The purchasing function is crucial in ensuring that consumer expectations are met by sourcing goods efficiently and effectively.