Final answer:
The incorrect reason for allocating joint costs per GAAP or managerial accounting is D) to evaluate the performance of division managers. While options A, B, and C are valid reasons, joint costs should not be used for manager performance evaluation as they are not controllable at the divisional level. The firm's accounting profit in the self-check question is $50,000.
Step-by-step explanation:
The question seeks to identify the option among A, B, C, and D that would not be a reason for allocating joint costs in accordance with Generally Accepted Accounting Principles (GAAP) or for managerial accounting purposes. The correct option is D) to evaluate the performance of division managers. Allocating joint costs to evaluate the performance of division managers is not advised because it can result in misleading information. The performance evaluation of managers should rather be based on factors within their control and joint costs are typically not controllable at the divisional level since they are incurred before the point at which the joint products are separable.
Option A) to calculate the cost of goods sold is a valid reason, as joint cost allocation allows for a determination of the cost of individual products sold. Option B) to analyze the profitability of various products is also valid because it helps in understanding the profitability of each joint product after the split-off point. Option C) for reimbursement of costs under a federal contract is a common necessity, as federal agencies often require cost allocation to ensure costs are appropriately charged to the specific contract.
To answer one of the self-check questions provided, the firm's accounting profit is calculated as total revenues minus explicit costs, which in this case would be $1,000,000 - ($600,000 + $150,000 + $200,000) = $50,000.
Regarding the social costs or gains not included in the marginal cost to the firm, these might include environmental costs (pollution, resource depletion), social costs (health issues, inequality), and social gains such as knowledge spillovers or community support that arise from a firm's operations but are not directly accounted for in prices or costs.