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Study Guide: Cost Accounting: Capital Budgeting Cost - Relevant Costs in Capital Decisions, Taxes, Depreciation, Tax Shield
Source: https://www.fatskills.com/accounting/chapter/cost-accounting-capital-budgeting-cost-relevant-costs-in-capital-decisions-taxes-depreciation-tax-shield

Cost Accounting: Capital Budgeting Cost - Relevant Costs in Capital Decisions, Taxes, Depreciation, Tax Shield

By Fatskills Exam Guides Team — the exam nerds behind 28,500+ quizzes and 2.1M practice questions across 500+ global exams.

⏱️ ~3 min read

? What this actually is

Relevant costs in capital decisions involve identifying and considering only those costs that will change as a result of a decision. In the context of taxes and depreciation, the depreciation tax shield is a key concept. It refers to the tax savings generated by depreciation expenses, which reduce taxable income. This matters because it affects the net present value (NPV) of capital investments, helping businesses make informed decisions about whether to invest in new assets.

? The core logic (or formula)

  1. Depreciation Tax Shield Formula: [ \text{Depreciation Tax Shield} = \text{Depreciation Expense} \times \text{Tax Rate} ]
  2. Depreciation Expense: The amount of depreciation deducted from taxable income.
  3. Tax Rate: The corporate tax rate.

  4. Net Present Value (NPV) Calculation: [ \text{NPV} = \sum \left( \frac{\text{Net Cash Inflows}}{(1 + r)^t} \right) - \text{Initial Investment} ]

  5. Net Cash Inflows: Cash inflows after considering depreciation tax shield.
  6. r: Discount rate.
  7. t: Time period.

  8. Relevant Costs: Only consider costs that differ between alternatives. Ignore sunk costs and allocated overheads.

  9. Tax Impact on Cash Flows: Adjust after-tax cash flows by subtracting the depreciation tax shield.

  10. Decision Rule: Accept the project if NPV > 0; reject if NPV < 0.

? Hidden rule nobody explains

In practice, the depreciation method (e.g., straight-line vs. accelerated) can significantly impact the timing of tax shields, affecting the NPV. Always consider the depreciation method used by the company when calculating the depreciation tax shield.

? Practical example / breakdown

Scenario: A company is considering purchasing a new machine for $100,000. The machine will generate annual cash inflows of $30,000 for 5 years. The company uses straight-line depreciation, and the corporate tax rate is 25%. The discount rate is 10%.

  1. Annual Depreciation Expense: [ \text{Depreciation Expense} = \frac{\$100,000}{5} = \$20,000 ]

  2. Annual Depreciation Tax Shield: [ \text{Depreciation Tax Shield} = \$20,000 \times 0.25 = \$5,000 ]

  3. After-Tax Cash Inflows: [ \text{After-Tax Cash Inflows} = \$30,000 - \$5,000 = \$25,000 ]

  4. NPV Calculation: [ \text{NPV} = \sum \left( \frac{\$25,000}{(1 + 0.10)^t} \right) - \$100,000 ] [ \text{NPV} = \$25,000 \times \left( \frac{1}{(1.10)^1} + \frac{1}{(1.10)^2} + \frac{1}{(1.10)^3} + \frac{1}{(1.10)^4} + \frac{1}{(1.10)^5} \right) - \$100,000 ] [ \text{NPV} = \$25,000 \times (0.909 + 0.826 + 0.751 + 0.683 + 0.621) - \$100,000 ] [ \text{NPV} = \$25,000 \times 3.790 - \$100,000 ] [ \text{NPV} = \$94,750 - \$100,000 ] [ \text{NPV} = -\$5,250 ]

Decision: Reject the project since NPV < 0.

? Your move today

Goal: Calculate the NPV of a capital investment considering the depreciation tax shield.

Step-by-step:
1. Identify the initial investment, annual cash inflows, depreciation method, tax rate, and discount rate.
2. Calculate the annual depreciation expense.
3. Determine the annual depreciation tax shield.
4. Adjust the after-tax cash inflows by subtracting the depreciation tax shield.
5. Calculate the NPV using the formula provided.
6. Make a decision based on the NPV.

What to save: A completed NPV calculation with all steps documented.

? Quick reference asset

Item Formula / Description Example
Depreciation Expense Initial Investment / Useful Life $100,000 / 5 = $20,000
Depreciation Tax Shield Depreciation Expense × Tax Rate $20,000 × 0.25 = $5,000
After-Tax Cash Inflows Cash Inflows - Depreciation Tax Shield $30,000 - $5,000 = $25,000
NPV Calculation ? (After-Tax Cash Inflows / (1 + r)^t) - Initial Investment See example above

Common mistakes & recovery

  • Common Error 1: Ignoring the depreciation tax shield in NPV calculations.
  • Recovery: Always adjust after-tax cash flows by subtracting the depreciation tax shield.
  • Common Error 2: Using the wrong depreciation method.
  • Recovery: Verify the depreciation method used by the company and apply it correctly.
  • Quick Check: Ensure the NPV calculation includes the depreciation tax shield and uses the correct depreciation method.
  • Exam Tip: Practice NPV calculations with and without the depreciation tax shield to understand the impact on decision-making.

? Completion check

"I can calculate the NPV of a capital investment considering the depreciation tax shield and make informed decisions based on the results."