Willingness to pay: turn stated amounts into a price test
Work from ten stated price thresholds to a $12-versus-$15 test, then see what a published pricing experiment reveals about question format and purchase evidence.
Willingness to pay is the maximum amount a buyer would pay for a defined offer in a particular situation. For an illustrative subscription delivering two 500 ml refills each month, the stated amounts below narrow the next price comparison to $12 and $15. The question asks about serious consideration, so its answers help choose prices to show buyers; they do not establish what buyers will purchase.
Willingness to accept asks the minimum compensation someone would require to give up a product or benefit. That differs from the maximum a buyer would pay to obtain an offer. For a subscription pricing decision, do not substitute one question for the other.
The monthly commitment is part of the offer
Keep two 500 ml refills each month and included delivery constant throughout the comparison. The subscription needs candidate monthly prices for a further test. Define the quantity, commitment and alternatives so buyers know what they are evaluating.
This offer supplies two 500 ml refills each month with delivery included. Thinking about your current alternatives and household budget, what is the highest monthly price at which you would seriously consider subscribing?
Allow a monetary amount, rejection of the subscription, and not enough information. Follow with the reason: what alternative, budget or expected use informed the answer? Someone can value the refills and still reject a monthly commitment. A question that forces everyone to type a number would conceal that distinction.
Decide whether a maximum is a task buyers can meaningfully perform. If people struggle to imagine the offer or produce round guesses, a displayed-price cell or concrete choice can be more direct. Do not interpret specificity to cents as evidence that the person has a stable threshold.
Ten stated amounts define the worksheet
The ten maximum-price answers in the example are $9, $11, $12, $14, $14, $16, $18, $19, $22 and $28.
Ten thresholds narrow the next price test
For each candidate monthly price, count answers at or above that amount. The table shows those exact points, rather than estimating demand between prices.
Candidate monthly price | Count and share |
|---|---|
$10 | Values at or above price: 9 of 10 Share of the ten amounts: 90% |
$12 | Values at or above price: 8 of 10 Share of the ten amounts: 80% |
$15 | Values at or above price: 5 of 10 Share of the ten amounts: 50% |
$20 | Values at or above price: 2 of 10 Share of the ten amounts: 20% |
Under the worksheet rule, a numeric answer at or above a candidate price counts toward its share. These shares show how to construct the curve; they do not estimate how many actual households will subscribe. The median is $15, halfway between the fifth value ($14) and sixth ($16). The mean is $16.30. Neither statistic is automatically the right commercial price.
The threshold arithmetic has a precise meaning: at price p, count numeric values at or above p and divide by ten. The $12 point includes 12 itself. The $15 point includes $16, $18, $19, $22 and $28. It does not include either $14. Anyone reconstructing the figure can follow that same rule.
The two middle thresholds set the median, while $28 pulls the mean upward. Neither calculation includes production, delivery or acquisition costs. A central value can summarize the answers while leaving the commercial choice unresolved.
The curve leaves important uncertainties unresolved
A threshold curve assumes a person whose maximum is $16 would consider the same offer at $15 and all lower prices. That monotonic rule makes the worksheet easy to interpret. Real responses can violate it: a very low price can imply poor quality, an alternative may be available only at one channel, or the person may reinterpret the subscription after seeing another amount.
The stated curve also assumes the answer remains meaningful at the point of purchase. Household budgets, stock, delivery windows and habit can intervene. Use those reasons to define the next comparison instead of applying an arbitrary discount to convert stated interest into a sales forecast.
For the refill offer, ask whether delivery is valuable because supplies are hard to obtain, or merely attractive in principle. A household that already buys refills cheaply on its usual shopping trip may give a low amount without disliking the product. A household with unreliable access may give a high amount for convenience. Those mechanisms suggest different targets and offer tests.
A noodle experiment tested open and closed price questions
In a study published in 2024, German university students evaluated sustainable South Korean instant noodles from a brand not sold locally. They answered an open amount question or closed Gabor-Granger questions, followed by an auction with binding purchase consequences. Of 400 initial students, 249 completed follow-up; 154 remained across conditions after excluding ratio outliers and auction WTP below €0.60 or above €3.50.
Question format | Mean individual stated-to-auction WTP ratio |
|---|---|
Open monetary amount | 1.23 |
Closed Gabor-Granger | 1.06 |
The researchers divided each student's stated amount by their auction WTP, then averaged those ratios. A ratio of 1.23 means a mean relative overstatement of 23%; 1.06 means 6%. These are unitless ratios, not purchase shares or ratios of the two group means. Source: Schmidt and colleagues (2024), Study 2, Table 3.
The selected student results don't supply a discount to apply to refill prices. The auction comparison also doesn't measure retail uptake or subscription renewal.
A broader 2020 meta-analysis by Schmidt and Bijmolt pooled 77 studies and found about 21% average hypothetical overstatement. Its size varied with method and context. That average is a reason to check stated amounts against purchase evidence, rather than reduce every answer by the same percentage.
The refill test still needs complete offers
For the refill subscription, the next step is to compare the same feasible offer at $12 and $15. First specify the quantity, delivery, monthly commitment and cancellation terms. Give each eligible household one assigned price before the interest question, keeping its usual purchase and buying nothing visible. Ask which alternative, budget or expected use informed the answer. Record the question wording and price exposure beside each result.
Rejection and missing information need different follow-ups
Answer to the refill prompt | Amount, state and follow-up |
|---|---|
“$14 per month” | Amount field: 14 Response state: Numeric consideration threshold Follow-up: What alternative and budget informed it? |
“Not for me at any price” | Amount field: Blank unless a stated coding rule requires zero Response state: Rejects the offer Follow-up: Which feature or occasion makes it unsuitable? |
“Does it include the container?” | Amount field: Blank Response state: Insufficient information Follow-up: Clarify the inclusion consistently before retesting |
No answer | Amount field: Blank Response state: Missing Follow-up: Check exposure and survey completion |
These additional response states do not change the ten-value example. In a real study, save the original amount and unit beside the state. “Does it include the container?” is an information gap; “not for me at any price” is offer rejection; no answer is missing evidence. Coding all three as zero mixes three different actions.
Show the distribution of numeric answers and a view of all eligible respondents. State in advance how rejection, insufficient information and missing answers affect each base. If valid rejection belongs in the latter, show it. If insufficient information is excluded from the numeric curve, show that base too. Neither a favorable curve from amounts only nor a pessimistic curve from zero-filled blanks should hide the people whose decision remains unresolved.
A high amount can reveal a different use case
The high value is useful because it asks the team to inspect context. Did the respondent understand two refills each month? Were they thinking about emergency delivery, a larger quantity or a costly current alternative? A verified unit misunderstanding can be corrected under a documented rule; an unusual but coherent use should remain visible.
For this set, removing $28 would change the mean to $15 and the numeric base to nine. That is arithmetic sensitivity, not a reason to delete the answer. The corrected description of the decision would have to say why the record was removed. A median can be robust to a high value while still failing to distinguish households the launch must serve.
Likewise, a low maximum may describe affordability, low expected usage or opposition to subscriptions. Reasons can reveal an audience opportunity or an offer problem that a central statistic cannot. The next research brief should use that explanation, not only carry forward a lower average.
The next claim determines the evidence you need
A stated question lets people evaluate an unlaunched offer and explain an objection. A transaction records buying under actual exposure, price, promotion and availability. Historical sales at two prices do not alone identify a causal price effect, because those conditions may have changed together.
If the next decision is “which monthly price deserves a trial?”, compare displayed feasible offers with the intended audience. If it is “will people reorder?”, observe repeat under a suitable pilot. Keep the trial’s opportunity base and duration with the result; a reorder count without knowing who had a chance to reorder does not answer the question.
For modeled thresholds, inspect task-relevant grounding and validation. The chart is still a summary of modeled answers, even when it resembles a demand curve. More rows or a smoother line do not change the evidence source.
The next comparison is $12 against $15
Eight numeric thresholds remain at $12 and five at $15. Those points create a clear next question. First confirm that either amount can cover the two refills and delivery under the business objective. Then compare the unchanged subscription at the two amounts, preserving comprehension, full intent categories and rejection reasons.
The threshold comparison cannot choose a winner without those economics and objectives. It can reduce a vague “what should we charge?” question to a candidate-price test. If neither amount works commercially, revise quantity, cadence, channel or commitment before testing the changed offer.
The useful deliverable names the candidates, the exact offer and audience, the objective and the next behavior evidence. That is more actionable than a headline willingness-to-pay figure detached from the subscription people imagined.
Further reading
For this subscription, a scoped Vensia study discussion should start with whether $12 and $15 are feasible and which buyer reaction would change the choice. Keep rejection of the monthly commitment separate from a low price threshold so the comparison can guide either a price test or a revised offer.
