What bypasses the overhead allocation questions and focuses on the relation of variable cost variances?

The contribution margin method focuses on the relationship between sales revenue and variable costs. It calculates the contribution margin (Sales - Variable Costs), which is the amount available to cover fixed costs and generate profit. This approach inherently separates costs by behavior (variable vs. fixed). By treating fixed costs, including fixed overhead, as period costs expensed in a lump sum, it bypasses the often-complex and arbitrary process of allocating fixed overhead to units of production. This allows management to focus directly on analyzing variances in revenue and variable costs (e.g., sales price, sales volume, material, and labor variances).

A. Internal revenue code method: This pertains to tax regulations, which often mandate absorption costing for external reporting, the opposite of the method described.

C. Direct costing method: While this is the underlying inventory-costing system that enables the contribution margin approach, the "contribution margin method" more precisely describes the analytical focus on variable cost relationships.

D. Ratemaking method: This is a pricing process used in regulated industries to set customer rates and is not a general method for internal variance analysis.

1. Garrison, R. H., Noreen, E. W., & Brewer, P. C. (2018). Managerial Accounting (16th ed.). McGraw-Hill Education. In Chapter 7, "Variable Costing: A Tool for Management," the text explains that the contribution format income statement, which is central to this method, "isolates costs by behavior" and is essential for various management analyses, bypassing fixed cost allocation issues inherent in absorption costing (pp. 288-291).

2. Horngren, C. T., Datar, S. M., & Rajan, M. V. (2015). Cost Accounting: A Managerial Emphasis (15th ed.). Pearson. Chapter 9, "Inventory Costing and Capacity Analysis," details how variable costing (which uses the contribution-margin format) avoids allocating fixed manufacturing costs to products. This makes it preferable for internal performance evaluations because it prevents changes in inventory levels from affecting operating income (pp. 308-311).

3. Drury, C. (2018). Management and Cost Accounting (10th ed.). Cengage Learning EMEA. Chapter 9 discusses how the contribution margin approach provides a better basis for decision-making and performance analysis by separating fixed and variable costs, thus avoiding the "arbitrary apportionment of fixed overheads" (Section 9.3).