Final answer:
The decline stage for a product occurs when sales for the product drop due to factors like shifts in consumer preferences, demographic changes, income decreases, and the availability of better substitutes.
Step-by-step explanation:
The decline stage for a product occurs when sales for the product drop. This is a phase in the product life cycle where the demand for a product decreases, often due to various market factors.
Such factors could include a shift in consumer tastes leading to lesser popularity, a fall in the population that is likely to purchase the product, a decrease in consumer income making the product a lower priority, and the introduction of superior substitutes that push the product out of favor.
Additionally, external factors such as improvements in technology could lead to a decreasing cost industry where firms see a reduction in average total costs due to economies of scale and greater efficiency.
When this happens, older products that do not benefit from such cost reductions may be pushed into the decline stage faster as newer, more cost-effective products take their place in the market.