Final answer:
Direct labor is an appropriate basis for assigning overhead costs to products when either direct labor constitutes a significant part of total product cost or a high correlation exists between direct labor and changes in the amount of overhead costs.
Step-by-step explanation:
Direct labor is an appropriate basis for assigning overhead costs to products when either (1) direct labor constitutes a significant part of total product cost or (2) a high correlation exists between direct labor and changes in the amount of overhead costs. In both scenarios, direct labor can serve as a reliable indicator of the amount of overhead costs incurred in producing a product.
For example, if direct labor makes up a significant portion of total product cost, it suggests that labor-intensive activities are a major driver of overhead costs. Similarly, if changes in direct labor consistently result in proportional changes in overhead costs, it indicates a strong correlation between the two, making direct labor an appropriate basis for assigning overhead costs.