Absorption Costing vs Variable Costing – Comprehensive Notes

Absorption Costing vs Variable Costing: Overview

  • Absorption costing: All manufacturing costs (variable and fixed) are treated as product costs and allocated to the product. They are included in Work in Process (WIP) and capitalized as inventory costs; expensed as Cost of Goods Sold (COGS) only when the goods are sold.

  • Variable costing: Only the variable manufacturing costs are treated as product costs and capitalized as inventory. Fixed manufacturing costs are treated as period costs and expensed in the period incurred.

  • Distinction matters for how income is reported and how inventory levels influence reported profits.

Key Concepts and Definitions
Variable Costing (Contribution Approach)

  • Contribution Margin (CM) = Revenue - Total Variable Cost

  • Operating Income (Variable Costing) = CM - Total Fixed Cost

  • Inventory is valued at variable manufacturing costs per unit; fixed overhead is expensed in the period incurred.

  • Income can differ from absorption costing when production and sales volumes differ.

  • Formula reminder: \text{CM} = \text{Revenue} - \text{Variable Manufacturing Costs} - \text{Variable SG&A (if treated as variable)}

Absorption Costing (GAAP)

  • All manufacturing costs (variable + fixed) are allocated to products and included in COGS once sold.

  • Income Statement structure (GAAP): Revenue - COGS = Gross Profit; Gross Profit - Operating Expenses (SG&A, R&D, etc.) = Operating Income.

  • Inventory values on the balance sheet include fixed manufacturing costs; profits may be influenced by the level of inventory due to fixed costs capitalized in inventory.

  • Primary difference: Fixed overhead is expensed in variable costing, but delayed/accelerated into COGS under absorption depending on production volume and inventory levels.

How to Compute Income Under Each Method
Variable Costing Income Statement (Structure)

  • Revenue

  • Variable Manufacturing Costs (including materials, direct labor, variable overhead)

  • Variable Selling, General & Administrative costs (if treated as variable)

  • Contribution Margin = Revenue - Total Variable Cost

  • Fixed Manufacturing Costs (period costs)

  • Fixed SG&A (period costs)

  • Operating Income (Variable Costing) = Contribution Margin - Fixed Costs

  • Key takeaway: Operating income in variable costing depends on sales, not on changes in inventory levels.

Absorption Costing Income Statement (Structure)

  • Revenue

  • Cost of Goods Sold (COGS) = Beginning Inventory + Total Manufacturing Costs - Ending Inventory

  • Gross Profit = Revenue - COGS

  • Operating Expenses (SG&A, R&D, etc.)

  • Operating Income (Absorption) = Gross Profit - Operating Expenses

  • Key takeaway: Fixed manufacturing costs are part of COGS and thus influenced by the amount of production and the level of ending inventory.

Core Formulas and Examples from the Transcript
Variable vs Absorption COGS (FIFO shown)

  • Variable Costing COGS: \text{Variable COGS}=\text{Beginning Inventory}{\text{variable}}+(\text{Variable Cost per Unit}\times \text{Units Produced})-\text{Ending Inventory}{\text{variable}}

  • Absorption Costing COGS: \text{Absorption COGS}=\text{Beginning Inventory}{\text{absorption}}+(\text{Total Manufacturing Costs})-\text{Ending Inventory}{\text{absorption}}

  • Where: \text{Total Manufacturing Costs}=\text{Variable Manufacturing Costs}+\text{Fixed Manufacturing Costs}

Example Cost-Per-Unit Details (Carter Corp, Year 2022)

  • Planned: variable production costs =20 per unit; fixed manufacturing costs =4{,}000 for the year; planned production =800 units; beginning finished goods =200 units.

  • Actual: production =600 units; sales =700 units; selling price =30; actual fixed costs equal budgeted fixed costs; actual variable cost per unit = budgeted variable cost per unit.

  • Actual per-unit costs:

    • Actual variable manufacturing cost per unit =20.00

    • Actual fixed manufacturing cost per unit =\frac{4{,}000}{600}\approx6.67 per unit

  • Non-manufacturing costs for the year: Marketing =0.50 per unit sold; Administrative =750 (fixed)

Ending and Beginning Inventory Cost Comparisons (Absorption vs Variable)

  • Ending Inventory: Variable =2{,}000; Absorption =2{,}667; Difference =-667 (absorption carries more into ending inventory)

  • Beginning Inventory: Variable =4{,}000; Absorption =5{,}000; Difference =-1{,}000

  • Change (Ending $-$ Beginning): Variable =-2{,}000; Absorption =-2{,}333; Difference =+333

Fixed Overhead Expensed in 2022 (Comparisons)

  • Under Variable Costing, fixed overhead expensed =4{,}000 (the entire fixed overhead for the period).

  • Under Absorption Costing, some fixed overhead is included in ending inventory; COGS reflects only the fixed overhead allocated to goods sold.

  • Example notes from the transcript show: Absorption COGS =18{,}333; Variable COGS has a variable component of 14{,}000 (i.e., 20\times700) and a difference of 333 due to inventory changes; Ending inventory under Absorption =100 units valued at 2{,}667 vs under Variable costing at 2{,}000; Beginning inventory under Absorption =5{,}000 vs Variable =4{,}000; Change results in a 333 difference in reported income.

Why Operating Income Differs Between Methods

  • The difference arises because fixed manufacturing costs are treated differently:

    • Variable costing: Fixed overhead is expensed in the period incurred, regardless of production volume.

    • Absorption costing: Fixed overhead is allocated to the product and expensed when the product is sold; inventory acts as a carrier for fixed overhead.

  • If production exceeds sales (production > sales): More fixed overhead gets capitalized in inventory under absorption costing, reducing COGS in the current period and increasing reported operating income compared to variable costing.

  • If sales exceed production (sales > production): Less fixed overhead is captured in ending inventory under absorption costing, increasing COGS and reducing reported operating income relative to variable costing.

  • Inventory valuation difference: Increasing or decreasing inventory changes how much fixed overhead sits in inventory vs. in COGS, thus shifting income between periods.

Practical Example: Income Manipulation with Absorption Costing

  • Increased production volume can be used to manipulate reported profits under absorption costing:

    • If production is increased relative to sales, more fixed overhead becomes part of ending inventory (balance sheet) and less is expensed in COGS (income statement), raising reported profit.

    • If there is no market for the additional production, the apparent profit increase is illusory and may mask lower actual demand or throughput efficiency.

  • Practical implication: Use variable costing for incentive-based decision-making and performance evaluation to avoid earnings manipulation via inventory buildup.

Practice Scenarios and Answers (Key Takeaways)
FIFO-Based COGS Under Variable vs Absorption Costing (For 2022)

  • Variable costing COGS formula: Beginning Inventory + Variable Manufacturing Costs - Ending Inventory

  • Absorption costing COGS formula: Beginning Inventory + Total Manufacturing Costs - Ending Inventory

  • These reflect the different treatments of fixed manufacturing costs within COGS under each method.

Operating Income Under Variable vs Absorption Costing (For a Given Period)

  • Variable Costing: Operating Income = Revenue - Variable COGS - Variable SG&A - Fixed Manufacturing - Fixed Administrative

  • Absorption Costing: Operating Income = (Revenue - COGS under Absorption - SG&A) with fixed manufacturing costs included in COGS

  • Example analysis: If production and sales volumes diverge, income numbers will diverge between the two methods because fixed overhead is treated as a period cost (variable costing) vs. a product cost (absorption costing).

Practice Question: Year 1–Year 2 Conceptual Understanding

  • Company’s production and sales patterns across years affect comparability of variable vs absorption-based income.

  • Typical result: When inventory levels rise in a year (production > sales), absorption costing tends to show higher income than variable costing for that year; when inventory declines (sales > production), absorption costing tends to show lower income than variable costing for that year.

Practical Implications and Countermeasures
Potential Incentives to Manipulate Income Under Absorption Costing

  • Managers may produce more units than sold to capitalize fixed overhead in inventory and inflate profits.

  • This can distort performance evaluation and bonus calculations.

Countermeasures and Best Practices

  • Use variable costing for incentive purposes and performance measurement where appropriate.

  • Implement careful budgeting and inventory planning to avoid unintended inventory buildup.

  • Incorporate an internal carrying charge for inventory to reflect holding costs.

  • Extend the performance evaluation period to smooth out year-to-year inventory effects.

  • Include nonfinancial metrics in performance evaluation to balance incentives.

Connections to Foundational Principles

  • This topic ties to cost behavior (fixed vs variable costs) and how cost allocation affects reported profitability.

  • Highlights how accounting choices can influence managerial decisions (e.g., production planning, inventory management).

  • Emphasizes the importance of ethical considerations and internal controls to prevent earnings manipulation.

Key Takeaways

  • Absorption costing capitalizes fixed manufacturing costs in inventory; variable costing expenses fixed overhead in the period.

  • Income under absorption vs variable costing may diverge when production differs from sales due to fixed overhead allocations.

  • Inventory levels can distort reported income under absorption costing, creating incentives to manipulate production.

  • Use variable costing for decision-making and performance evaluation where you want to align incentives with the actual economic activity, and apply broader controls to mitigate manipulation risks.

Main Formulas

  • Variable COGS: \text{Variable COGS}=\text{Beginning Inventory}{\text{variable}}+(\text{Variable Cost per Unit}\times \text{Units Produced})-\text{Ending Inventory}{\text{variable}}

  • Total Manufacturing Costs: \text{Total Manufacturing Costs}=\text{Variable Manufacturing Costs}+\text{Fixed Manufacturing Costs}

  • Absorption COGS: \text{Absorption COGS}=\text{Beginning Inventory}{\text{absorption}}+\text{Total Manufacturing Costs}-\text{Ending Inventory}{\text{absorption}}

  • Fixed overhead per unit: \text{Fixed overhead per unit}=\frac{F}{Q} where F=\text{Total Fixed Manufacturing Costs} and Q=\text{Units Produced}

Example Per-Unit Costs (from Carter Corp 2022)

  • Variable manufacturing cost per unit =20