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The endowed progress effect and the car wash loyalty card
Nunes and Drèze (2006) report that artificial head-start progress raised completion and shortened completion time. Secondary summaries place a loyalty card test at an unnamed car wash. The paper's completion percentages could not be checked and are not given.
- Where it sits
- Academic psychologyResearch published for other researchers and students.
- Evidence level
- Independent experimentIndependent research, with its design and limits stated.
- Sources inspected
- 3 of 32 with the relevant text, company document or archive item checked, 1 as an abstract or reference article, 0 not verified.
What happened
Joseph Nunes and Xavier Drèze published a paper in the Journal of Consumer Research in 2006 that named the endowed progress effect. Their best-known field test is usually described with car wash loyalty cards. A Wharton summary says 300 customers received cards and calls the venue only a car wash, with no business named. Both card types needed eight purchases for a free wash.
The psychological idea
One card had eight empty spaces. The other had ten spaces with two already stamped, so the work required was the same. The authors' abstract says artificial advancement toward a goal raised the likelihood of completion and cut completion time. They suggest the effect depends on perceived progress rather than a wish not to waste the head start. They name two moderators: the reason given for the endowment and the currency in which progress is recorded.
In practice
The documented practice is a pre-stamped loyalty card. Wharton's summary and a consultancy write-up both report that customers with the pre-stamped card were more likely to finish and finished sooner. Neither gives completion rates, so none are given here. No source opened shows that a named business adopted the design because of the paper.
Why it mattered
The study is cited for the idea that perceived progress, not the effort required, can change whether people finish a loyalty card. It gives the loyalty topic a field experiment to set beside company case histories.
Limits and qualifications
Only the abstract of the paper and two secondary summaries were readable, so design details and numbers were not checked against the full text. The abstract does not mention a car wash; that setting comes from the summaries. The summaries give no completion rates and do not describe the customers. The field test is one car wash. The authors' explanation, perceived progress, is their interpretation, and tests of rival explanations were not read.
Evidence behind the claims
The abstract says artificial advancement toward a goal increased the likelihood of task completion and decreased completion time.
The authors suggest the effect depends on perceptions of task completion rather than a desire to avoid wasting the endowed progress.
The abstract lists two moderators: the reason given for the endowment and the currency in which progress is recorded; it does not mention a car wash.
A Wharton summary says 300 car wash customers received loyalty cards that required eight purchases, with a ten-space version giving two free stamps on enrollment, and describes the venue only as a car wash without naming it.
Both secondary summaries say the pre-stamped group completed the card more often or sooner, but neither gives completion rates.
People involved
- Joseph C. Nunes. Co-author, marketing researcher
- Xavier Drèze. Co-author, marketing researcher
In the Psy101 course
- OpenStax Psychology 2e, section 6.3: Operant ConditioningChapter 6, Learning. Concept. The section discusses this topic.The operant conditioning section covers rewards and sticker charts in behavior modification.
- OpenStax Psychology 2e, section 10.1: MotivationChapter 10, Emotion and Motivation. Context. Nearest related section; it does not discuss this topic by name.Nearest related section: it covers extrinsic rewards and mentions goals only in passing.
This is course relevance only. It is not evidence for the historical or corporate claims on this page.See the full course map.
Sources and inspection
3 of 3 sources were opened and read at the level shown. A source marked as not verified supports no claim on this page by itself.
- [1]The Endowed Progress Effect: How Artificial Advancement Increases EffortNunes, J; Drèze, X. Journal of Consumer Research 32(4): 504-512, Oxford University Press, 2006. Journal article. Primary source.Abstract or publisher record onlyReviewer read the publisher abstract page as returned by the fetch tool; the full text was not available. The page does not mention a car wash.
- [2]The Lowdown on Customer Loyalty Programs: Which Are the Most Effective and WhyKnowledge at Wharton. Knowledge at Wharton, 2006. News report. Secondary account.Relevant text checkedReviewer read the page as returned by the fetch tool (podcast page dated 6 September 2006): 300 customers, eight purchases, ten-space card with two stamps, venue not named, no completion rates.
- [3]Endowed Progress EffectThink Insights. Think Insights, 2026. Reference work. Secondary account.Relevant text checkedReviewer read the consultancy page as returned by the fetch tool: ten-stamp card with two granted versus eight-stamp card, endowed group completed more often and sooner, no figures, car wash not named.
Access note: The paper's full text was not opened. Completion percentages and a tracking window repeated elsewhere were not found in any opened source, so they are not stated.
Independent source review: Claude review agent, independent of the research agent, 2026-10-21. Verdict: pass-with-edits.