Separate sunk cost from a new spending choice
See this course’s project requirements
An original financial decision-case comparison and rule test covering anchored prices, sunk costs, recurring charges and delayed spending with a prewritten decision rule.
Keep your working files in your own notebook or software. Save a private description, checklist, and work link in My Proof.
What to include
- A controlled price-anchor comparison and choice explanation.
- A sunk/avoidable cost decision table.
- A twelve-month price comparison and crossover calculation.
- A dated value-comparison record and access-constraint note.
- A framed-choice comparison with explicit design limitations.
- A complete financial decision-case comparison and rule-retest log.
Review and revise
Use these criteria to check your work and choose what to improve.
- All supplied records reconcile and the decision uses the named case rules.
- Calculations show units, intermediate values and a second check.
- Changed-input practice revises the affected result and identifies uncertainty.
- The final project combines six lesson records, separates fictional assumptions from current rules, and states a supported next step.
Want more background?
The idea in everyday life
This is an original fictional practice case. No account, payment, personal record or outside participation is required. A fictional event ticket already cost $40 and cannot be refunded or sold. Going now requires $15 transport; staying home costs $0. Enjoyment and time preferences are unspecified.
A past unrecoverable payment is the same under both new alternatives; compare what can still change.
Separate sunk cost from a new spending choice — worked practice
A past unrecoverable payment is the same under both new alternatives; compare what can still change.
Use paper or a local table; label all amounts as fictional USD unless the case names another unit. A fictional event ticket already cost $40 and cannot be refunded or sold. Going now requires $15 transport; staying home costs $0. Enjoyment and time preferences are unspecified.
Sunk and incremental costs
Paste at A1.
| AInput or record | BSupplied value |
|---|---|
| Past unrecoverable ticket USD | 40 |
| New transport if going USD | 15 |
| New money if staying USD | 0 |
| Refund or resale option | None |
| Enjoyment and time preference | Unspecified |
Copy as plain text
1. Step 1: Label the $40 as already paid and unrecoverable
Label the $40 as already paid and unrecoverable.
You should see: The $40 is present in both alternatives.
A past unrecoverable payment is the same under both new alternatives; compare what can still change.
2. Step 2: List future avoidable money costs
List future avoidable money costs.
You should see: Go: $15; stay: $0.
Keep this intermediate result so the final decision can be checked.
3. Step 3: Calculate the incremental money cost of going
Calculate the incremental money cost of going.
You should see: $15.
Keep this intermediate result so the final decision can be checked.
4. Step 4: Write the missing-value questions
Write the missing-value questions.
You should see: Enjoyment, time and commitments can matter; the old payment alone does not require going.
Keep this intermediate result so the final decision can be checked.
What to finish
A sunk/avoidable cost decision table.
Watch for this
Adding a past unrecoverable payment again to justify new spending.
How can I tell I understand it?
Identify an unrecoverable cost and calculate only the future difference between alternatives on the supplied changed case while preserving the stated rule and checking the final record.
Quick knowledge check
Answer all 3 questions. Get at least 2 right and the lesson completes automatically.
You’ll get an explanation for each answer. Signed in? Your results save to your account.
Pass the check. We’ll save the progress.
Answer all 3 questions above and get at least 2 right. You can review the explanations and try again.
Go to the knowledge checkTools, templates, and lesson sources
Tools and templates
Tools open in a new tab so you can keep your place here.
Sources and further reading
Explore the references behind this lesson.
Source & access notes · checked 2026-10-01
Official page opened/read during Money expansion authoring; checked the relevant concept and access state. These sources do not establish funding eligibility.
Access: Official resource page and its readable overview/transcript inspected; no external LMS lesson or media playback is claimed.
Reuse: Original fictional practice, questions and calculations; paraphrased concepts with a source link. No source exercise copied.
Report a problem with this lesson
Tell us what went wrong. Please leave out personal information and private project contents.