Bandwagon Effect
Edited by Paweł Raja, PhD · Published
Definition
Bandwagon Effect is the bandwagon effect is the tendency to adopt a belief, product or behavior because many other people have already adopted it, so that popularity itself becomes a reason to join, independent of the thing's merits.
- Also known as:
- Bandwagon bias
- Category:
- Social Influence
- Impact:
- High
- Landmark study:
- Leibenstein (1950)
- Evidence here:
- 6 cited studies
Why it happens: the psychology of bandwagon effect
The economist Harvey Leibenstein (1950) gave the term its formal meaning: a bandwagon effect exists when demand for a good rises because other people are consuming it. He set it beside the snob effect, where demand falls because others are buying, and the Veblen effect, where demand rises because the price is conspicuously high. The phrase itself comes from American politics, where 'jumping on the bandwagon' meant joining a campaign that looked like a winner.
Part of the bandwagon effect is informational, and for each individual it can even be rational. If many people chose something, they may know something you don't. Banerjee (1992) and Bikhchandani, Hirshleifer and Welch (1992) showed that when people decide one after another and can see earlier choices but not the reasons behind them, it can be optimal to set aside your own information and follow the crowd. The result is herd behavior or an informational cascade: everyone copies, no new information enters, and the crowd can lock onto the wrong answer. Because the cascade rests on little real evidence, it is also fragile, which helps explain sudden fads and equally sudden reversals.
The other part is normative: the wish to fit in and be on the winning side. In Asch's conformity experiments, participants often went along with a unanimous group that gave an obviously wrong answer about line lengths. Siding with the majority avoids the discomfort of standing out, which is why bandwagon effects are strong in fashion, politics and online pile-ons.
Bandwagons compound. Salganik, Dodds and Watts (2006) built an online music market with 14,341 participants. When people could see how often each song had been downloaded, success became both more unequal and less predictable: the best songs rarely did badly and the worst rarely did well, but almost any other outcome was possible depending on early downloads. Muchnik, Aral and Taylor (2013) found the same snowballing with up-votes on a news site, although artificial down-votes were largely corrected by later users. The bandwagon effect is closely related to social proof, the availability cascade and groupthink.
Bandwagon Effect examples
In a randomized experiment on a social news website, comments that randomly received one artificial up-vote went on to attract more positive ratings: positive ratings became 32% more likely, and the comments' final scores ended up 25% higher on average (Muchnik, Aral & Taylor, 2013).
- Buying a stock or cryptocurrency after it has already risen sharply, mainly because everyone you know seems to be making money on it.
- Trying a fad diet or supplement because it is trending on social media, before checking whether there is any evidence that it works.
- In a meeting, once the first two or three senior people back a proposal, the rest of the room lines up behind it and doubts go unspoken.
- Picking the restaurant with a line outside over the empty one next door, without knowing anything else about either.
- A product with thousands of reviews looks safer than an equally good one with a few dozen, so the leader keeps collecting reviews and the gap widens.
- Undecided voters drifting toward whichever candidate the polls show pulling ahead.
- A sneaker becomes desirable because everyone is wearing it, until it is so common that trend-setters drop it — the 'snob effect' that is the bandwagon's mirror image.
Bandwagon effect vs social proof
The two terms describe the same territory from different ends. Social proof is the psychological mechanism: treating what other people do as evidence about what is right. The bandwagon effect is the pattern that results when that mechanism runs across a whole population, so that adoption accelerates simply because adoption is already high.
A useful test is whether the crowd has independent information. Following others is a sensible shortcut when they reached their choices separately — a busy restaurant in a city you don't know. It becomes a bandwagon bias when the crowd is mostly copying itself, so the apparent consensus carries far less information than its size suggests.
Bandwagon effect, herd behavior and informational cascades
Herd behavior is the economist's term for many people making the same choice by imitating one another, especially in financial markets. Informational cascades are a specific model of how herding starts and why it can be wrong. The bandwagon effect is the broader, everyday label, and it also covers the purely social wish to be on the popular side even when you don't think the crowd knows more than you.
How to avoid the bandwagon effect
- Ask whether the crowd has independent information. Many people agreeing counts for a lot only if they reached their views separately; if they are copying one another, a thousand votes may carry the evidence of a handful.
- Form your own view before you look at the numbers. Write down your rating, estimate or preference first, then check the consensus.
- Look for reasons rather than counts. Reviews that explain why, test results and track records are stronger evidence than likes, downloads or sales rankings.
- In groups, collect opinions independently — written votes or anonymous rounds — before discussion starts, and let the most senior person speak last.
- Be extra skeptical when rising popularity or rising prices are the main reason to buy. You may be late on a bandwagon rather than early on an opportunity.
How to design for it (nudge strategy)
Show genuine, verifiable adoption figures when the popular choice is also the good one ("most people on your team have enrolled"), and hide running vote counts or rankings when you need independent judgments, such as reviews, expert polls or hiring panels.
Ethical use: design for choices people would endorse on reflection — a nudge, not sludge. Be transparent and keep opting out easy.
Key studies
Formalized the bandwagon effect as demand for a good increasing because others consume it, alongside the opposite snob effect and the price-driven Veblen effect.
Leibenstein, H. (1950). Bandwagon, snob, and Veblen effects in the theory of consumers' demand. Quarterly Journal of Economics, 64(2), 183–207. DOI →
Showed that people who observe earlier decisions can rationally do what others are doing rather than use their own information, producing herd behavior and an inefficient outcome.
Banerjee, A. V. (1992). A simple model of herd behavior. Quarterly Journal of Economics, 107(3), 797–817. DOI →
Introduced informational cascades, in which it is optimal to follow the behavior of those ahead regardless of one's own information, explaining both conformity and the fragility of mass behavior.
Bikhchandani, S., Hirshleifer, D., & Welch, I. (1992). A theory of fads, fashion, custom, and cultural change as informational cascades. Journal of Political Economy, 100(5), 992–1026. DOI →
In an online music market with 14,341 participants, letting people see others' downloads increased both the inequality and the unpredictability of which songs succeeded.
Salganik, M. J., Dodds, P. S., & Watts, D. J. (2006). Experimental study of inequality and unpredictability in an artificial cultural market. Science, 311(5762), 854–856. DOI →
A random initial up-vote raised the likelihood of positive ratings by 32% and final ratings by 25% on average; artificial down-votes were largely corrected by later users.
Muchnik, L., Aral, S., & Taylor, S. J. (2013). Social influence bias: A randomized experiment. Science, 341(6146), 647–651. DOI →
Key research
- Misperceived Social Norms: Women Working Outside the Home in Saudi ArabiaLeonardo Bursztyn, Alessandra L. González, David Yanagizawa-Drott · American Economic Review (2020)
Related biases
Bandwagon Effect: frequently asked questions
What is the bandwagon effect?
The bandwagon effect is the tendency to adopt a belief, product or behavior because many others already have. Popularity becomes a reason in itself, so things that are already popular tend to become more popular.
What is an example of the bandwagon effect?
Buying an asset because its price is soaring and everyone is talking about it, choosing the product with the most reviews, or backing the candidate who is ahead in the polls.
Is the bandwagon effect the same as herd behavior?
They overlap heavily. Herd behavior usually refers to people imitating one another's choices, especially in markets, often for informational reasons. The bandwagon effect is the broader term and also includes joining in simply to fit in or be on the winning side.
What is the opposite of the bandwagon effect?
Leibenstein (1950) described the snob effect: demand for something falls because many others have it, as people seek exclusivity. Both effects can apply to the same product at different stages of its popularity.
Why is it called the bandwagon effect?
A bandwagon was the wagon that carried a band in a parade. In 19th-century American political campaigns, supporters who wanted to be associated with a likely winner were said to 'jump on the bandwagon,' and the phrase came to mean joining whatever seems to be succeeding.
Is the bandwagon effect always bad?
No. Following others is often a reasonable shortcut when they have better information than you. It becomes a bias when the crowd is mostly copying itself, or when popularity is mistaken for quality.
Cite this page
Raja, P. (Ed.). (2026, 8 Oct 2026). Bandwagon Effect. Behavioral Economics Lab. https://www.behavioraleconomicslab.com/biases/bandwagon-effect