Does the Availability Heuristic Sell

Why We Act · 26 October 2026 · Reviewed by Faisal Zaidi

Vivid news does shift what people buy, but the evidence is narrower than the heuristic's name suggests. Insurance, travel and meat show local effects that fade, and the one study that tested media exposure against personal experience found media played a minor role.

Answer to the question

Why does vivid news change what we buy?

Vivid news makes a risk easier to recall, and people tend to judge easily recalled risks as more likely. Purchases then move: flood insurance take-up rose after floods, and road deaths rose after 11 September 2001 as air travel fell. The effects are local and fade, and the studies do not isolate the heuristic as their cause.

Key takeaways

Lichtenstein and colleagues (1978) asked people to compare causes of death. As Kahneman reports it, strokes cause almost twice as many deaths as all accidents combined, yet 80 per cent of respondents judged accidental death more likely.
Schwarz and colleagues (1991) found that people who recalled 12 examples of their own assertive behaviour rated themselves as less assertive than those who recalled 6. Ease of recall, not the number recalled, carried the signal.
Weingarten and Hutchinson (2018) pooled 142 papers and 263 studies on ease of retrieval. The effect was medium-sized, ease mediated a third to a half of it, and publication bias reduced the estimate by up to a third.
Pachur, Hertwig and Steinmann (2012) tested the availability heuristic against the affect heuristic in two student studies. Recall of risks in a person's own network matched judgements best, and media exposure played a minor role.
Gallagher (2014) found that flood insurance take-up spikes the year after a flood and then declines to baseline. Non-flooded communities in the same television market raised take-up at one-third the rate of flooded ones.

In the year after a county is hit by a declared flood, flood insurance take-up there rises by nearly 10 per cent, then drifts back to baseline. The availability heuristic is the usual explanation: a vivid recent event makes a risk feel larger, so people buy cover. The pattern is real and has been measured across the United States. The explanation is only partly supported by the research.

Strokes, Accidents and Tornadoes

Amos Tversky and Daniel Kahneman named the availability heuristic in 1973. It is the habit of judging how common something is by how easily examples come to mind. In the opening chapter of Thinking, Fast and Slow, Kahneman applies it to the news: the ease with which issues are retrieved from memory is, he writes, "largely determined by the extent of coverage in the media."

Largely determined by the extent of coverage in the media.

The standard demonstration is a set of comparisons between causes of death, run by Sarah Lichtenstein and colleagues, and reported by Kahneman in chapter 13. Strokes cause almost twice as many deaths as all accidents combined, yet 80 per cent of respondents judged accidental death more likely. Tornadoes were seen as deadlier than asthma, which kills about 20 times as many people. Lightning was judged less likely to kill than botulism, though it is 52 times more frequent.

The estimates were highly consistent across respondents and systematically wrong: small frequencies were overestimated, large ones underestimated, and some causes were exaggerated at any given true frequency. The authors traced the distortions to disproportionate exposure, memorability and imaginability, and found that people could not correct for them even when told to try. A news report supplies all three.

Ease, Not Quantity, Carries the Signal

The name of the availability heuristic suggests that people count the examples they can recall. The best-known experiment says otherwise. Norbert Schwarz and colleagues asked participants to recall either 6 or 12 examples of their own assertive behaviour and then to rate how assertive they were. Twelve is hard to produce. Those who struggled through twelve rated themselves as less assertive than those who found six easily. What they read off was the effort of recall, not the size of the pile.

When the difficulty was given another cause, the effect disappeared. In the version Kahneman describes, participants told that background music would hinder recall rated themselves as equally assertive after twelve examples as after six. Kahneman suggests the process might better be called an "unexplained unavailability" heuristic, because the inference depends on recall feeling harder than it should.

How firm is the result? A meta-analysis led by Evan Weingarten pooled 142 papers, 263 studies and 582 effect sizes on the few-versus-many manipulation. On average it produced a medium-sized effect. Subjective ease mediated about a third to a half of it, so other processes are involved, and publication bias reduced the estimate by up to a third once corrected. The mechanism is a modest regularity. [The Psychology You Learned Didn't Replicate](https://thewhyweproject.com/articles/the-psychology-you-learned-didnt-replicate) looks at why published effects shrink when they are pooled or repeated.

Kahneman also reports a condition under which ease stops mattering. Students were asked to recall either three or eight behaviours bearing on the risk of cardiac disease. Those with no family history of it went by fluency. Those with a family history showed the opposite pattern and went by content. When a risk touches the person, what the examples say counts for more than how easily they arrive.

Does the News Supply the Examples?

Kahneman's sentence about media coverage reads as common sense. A direct test of the availability heuristic against its rivals, with media exposure measured, is rarer. Thorsten Pachur, Ralph Hertwig and a colleague pitted the availability heuristic against the affect heuristic in two studies with student samples, using frequency judgements, the value of a statistical life and perceived risk, across cancer and a range of other causes of death.

Availability from recall, which draws on direct experience of risks within a person's social network, best matched the answers. Feelings about the hazard mattered more for perceived risk and the value of a life than for frequency estimates. Media exposure played a minor role. The authors also found signs that the two heuristics can operate together. Kahneman reports a related result from the group around Paul Slovic: people who judged the risks and benefits of technologies such as water fluoridation and food preservatives gave implausibly negative correlations between the two, and a passage describing only a technology's benefits lowered its perceived risk, although it contained no evidence about risk.

For a marketer the finding moves attention from the broadcast to the buyer's own circle, which is where the availability heuristic seems to draw its examples. The examples that come to mind most easily may be the ones a neighbour or a relative supplied, and a news story reaches a shopper at full strength only when it resembles something already close. [Denominator Neglect and the Bigger Bowl](https://thewhyweproject.com/articles/denominator-neglect-and-the-bigger-bowl) takes up a related judgement error from the same book.

Insurance, Beef and the Interstate

Purchases are where the chain meets money, and three bodies of evidence cover it. Kahneman notes that a researcher had seen, before he and Tversky published, that availability explains insurance and protective action after disasters.

Justin Gallagher built a nationwide panel of large regional floods and flood insurance policies in the United States. Take-up spikes in the year after a flood, by nearly 10 per cent in the American Economic Association's summary of the study, and then declines steadily to baseline. Residents of communities that were not flooded, but shared a television market with ones that were, raised take-up at one-third the rate of the flooded communities. The signal travelled through a shared broadcast area. Gallagher's own reading is that take-up fits a Bayesian learning model that allows for forgetting, a description a rational buyer could satisfy as easily as a biased one.

Travel is the dramatic case. After 11 September 2001 air travel fell. Gerd Gigerenzer reported that interstate driving rose for about a year and that fatal crashes exceeded the baseline in every month of it, and he estimated that about 1,500 Americans died on the roads while trying to avoid the fate of the flight passengers. He frames this as dread risk, a fear of rare events that kill many people at once. Dread overlaps with availability but is a separate account: one rests on how a hazard feels, the other on how readily it comes to mind.

The size of the effect is disputed. A later re-analysis of the first three months found 1,018 additional road deaths, against the 353 in Gigerenzer's 2004 paper. It also found that most of the rise was on local roads and that pedestrians and cyclists made up a disproportionate share, which counts against a simple swap of flights for car journeys. How rare, vivid risks come to carry more weight than their probability deserves is the subject of [Why a 1 Per Cent Chance Feels Bigger](https://thewhyweproject.com/articles/why-a-1-per-cent-chance-feels-bigger).

A second city offers a comparison. After the London bombings of 7 July 2005, Peter Ayton and colleagues found Underground journeys 7.1 per cent below prediction and bicycle journeys 10.6 per cent above it. Bicycle casualties ran 15.4 per cent above prediction, an estimated 214 extra, with no significant rise in car casualties. The authors call their evidence correlational, and they conclude that conditions in the environment decide whether fear turns into harm. The substitute purchase was the one the city made easy.

Food gives the quietest result. A model of how publicised food safety information affects US meat demand found that the average response was small, much smaller than the response to price. Responses during prominent food safety events were much larger, but they faded quickly and showed no clear lagged effects.

What Survives Between Headline and Till

Link in the chain	Strongest evidence here	Standing
Ease of recall shapes judgement	Schwarz and colleagues (1991); Weingarten and Hutchinson (2018)	Real and medium-sized, with ease mediating part of it
The news supplies the examples	Pachur, Hertwig and Steinmann (2012)	Weak; personal experience mattered more
Judgement changes what is bought	Gallagher (2014); Gigerenzer (2006); Piggott and Marsh (2004)	Present, local and fading; size disputed
The heuristic is the cause	Gallagher's learning-with-forgetting fit	Not isolated

Vivid news does change purchases, mostly where the hazard is local, the purchase is easy to adjust and the story arrives through the buyer's own market. As a label, the heuristic fits part of that and not the rest. Feelings about the hazard, recall of examples and ordinary learning all fit the flood-cover and travel data. For a seller, the evidence supports planning for a local bump that is brief for goods that are easy to substitute, such as meat, and lasts longer for protection that has to be bought and renewed, such as an annual policy.

Common questions

Why does vivid news change what we buy?

Is the availability heuristic still considered valid?

As a description, yes. The ease-of-retrieval effect that underlies it was pooled across 263 studies and came out medium-sized, with ease mediating a third to a half of it and publication bias reducing the estimate by up to a third. Kahneman himself suggests the mechanism is better described as unexplained unavailability.

Does media coverage drive the availability heuristic in shoppers?

Kahneman says coverage largely determines which issues come to mind. In two student studies by Pachur, Hertwig and a colleague, however, recall of risks in a person's own network matched risk judgements best and media exposure played a minor role.

How long does a news story affect buying?

It depends on the purchase. Flood insurance take-up spiked the year after a flood and declined steadily to baseline. Meat demand responded to prominent food safety events much more strongly than average, and the response faded quickly.

Sources

Tversky, A., & Kahneman, D. (1973). 'Availability: A heuristic for judging frequency and probability.' Cognitive Psychology, 5(2), 207-232. doi:10.1016/0010-0285(73)90033-9

Lichtenstein, S., Slovic, P., Fischhoff, B., Layman, M., & Combs, B. (1978). 'Judged frequency of lethal events.' Journal of Experimental Psychology: Human Learning and Memory, 4(6), 551-578. doi:10.1037//0278-7393.4.6.551

Schwarz, N., Bless, H., Strack, F., Klumpp, G., Rittenauer-Schatka, H., & Simons, A. (1991). 'Ease of retrieval as information: Another look at the availability heuristic.' Journal of Personality and Social Psychology, 61(2), 195-202. doi:10.1037/0022-3514.61.2.195

Weingarten, E., & Hutchinson, J. W. (2018). 'Does ease mediate the ease-of-retrieval effect? A meta-analysis.' Psychological Bulletin, 144(3), 227-283. doi:10.1037/bul0000122

Pachur, T., Hertwig, R., & Steinmann, F. (2012). 'How do people judge risks: Availability heuristic, affect heuristic, or both?' Journal of Experimental Psychology: Applied, 18(3), 314-330. doi:10.1037/a0028279

Gallagher, J. (2014). 'Learning about an infrequent event: Evidence from flood insurance take-up in the United States.' American Economic Journal: Applied Economics, 6(3), 206-233. doi:10.1257/app.6.3.206

Gigerenzer, G. (2004). 'Dread risk, September 11, and fatal traffic accidents.' Psychological Science, 15(4). doi:10.1111/j.0956-7976.2004.00668.x

Gigerenzer, G. (2006). 'Out of the frying pan into the fire: Behavioral reactions to terrorist attacks.' Risk Analysis, 26(2), 347-351. doi:10.1111/j.1539-6924.2006.00753.x

American Economic Association. 'Will flood insurance take-up spike?' AEA Research Highlights, summarising Gallagher (2014). https://www.aeaweb.org/research/will-flood-insurance-takeup-spike

Sivak, M., & Flannagan, M. J. (2004). 'Consequences for road traffic fatalities of the reduction in flying following September 11, 2001.' Transportation Research Part F, 7(4-5), 301-305. https://swov.nl/en/publicatie/consequences-road-traffic-fatalities-reduction-flying-following-september-11-2001

Ayton, P., Murray, S., & Hampton, J. A. (2019). 'Terrorism, dread risk and bicycle accidents.' Judgment and Decision Making, 14(3), 280-287. https://dlab.sauder.ubc.ca/sjdm/journal/18/181012/jdm181012.html

Piggott, N. E., & Marsh, T. L. (2004). 'Does food safety information impact U.S. meat demand?' American Journal of Agricultural Economics, 86(1), 154-174. doi:10.1111/j.1467-8276.2004.tb18463.x

Kahneman, D. (2011). Thinking, Fast and Slow. Farrar, Straus and Giroux. Opening chapter; chs. 12 and 13 (pp. 129-145), as recorded in the vault's digests of the book.