Willingness to pay is not a fixed customer property.
Willingness to pay is not a fixed customer property. It changes with the offer, quantity, risk, alternatives, framing and the real ability to buy. Declarative research can map a range; only a credible choice situation gets closer to behaviour. The final price should maximise an economic consequence, not the average response.
Decision.
Choose the measurement method and candidate price according to novelty, alternatives, bias risk and the economic decision. Define the real choice: offer, unit, alternatives, channel, horizon and consequence. Use declarative work to explore, conjoint to separate attributes, then a preorder or field test to validate finalist prices. Randomise order, limit anchors, include non-purchase, check understanding and convert every finalist price into contribution by segment, projecting acquisition, retention and migration. Publish a range and the price that remains preferable under uncertainty.
Worked example.
Van Westendorp places the acceptable range at €42–€68. Gabor-Granger maximises revenue at €59; conjoint suggests €64; a preorder test confirms 18% conversion at €59 versus 15% at €64. With a €28 variable cost and 10,000 prospects: 10,000 × 18% × €31 = €55,800 at €59; 10,000 × 15% × €36 = €54,000 at €64. Launch at €59; retain €64 as a richer-package or segment scenario to test.
Checks and limits.
Make offer, alternatives and purchase consequence explicit; include non-purchase; and require at least one behavioural proof. Declarative answers remain anchor- and desirability-sensitive. Field tests can contaminate customers, change reference price or raise fairness issues; estimates age quickly when competitors, inflation or the package change.
Resources and sources.
Download the method comparator. Related: link price and demand response, build a price test, turn value into price tiers. Sources: Gabor & Granger (1966); McFadden (1974); Wertenbroch & Skiera (2002).