Economists find more than one-in-10 online reviews 'fake'

10 August 2023 3 min. read
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Online reviews were once thought to be a path to democratising feedback – allowing users to recommend good and services to each other instantly, and helping small businesses build customer bases in the process. But a new study suggests more than one-in-ten online reviews is actually fake, reducing the credibility of review platforms, and making it more difficult to rely on their recommendations.

Online reviews can help consumers learn about products, services, and company reputations, and inform companies about consumer experiences and satisfaction. But increasingly, ‘bad faith actors’ are also typing out fake reviews, or reviews that do not reflect a customer's experience, to influence consumer behaviour, and enhance or reduce businesses' reputations.

For example, earlier in 2023, Disney’s ‘live-action’ (if you ignore the talking CGI sea animals) of ‘The Little Mermaid’ was ‘review-bombed’ by individuals taking exception to its politics. After a racist backlash to the film’s casting of Black actor Halle Bailey in the lead role, 39% of user-reviews posted on IMDb feature the lowest possible 1-star ratings – vastly more negative than most professional reviewers, largely who gave it mid-range reviews – suggesting many were simply using their review to make an example of art they were ideologically opposed to.

Economists find more than one-in-10 online reviews 'fake'

On the other side of the divide, companies have also been alleged to be using review platforms anonymously to enhance their standing among consumers. For instance, one recent BBC investigation found that private medical clinics across Britain are boosting their profiles online with scores of fake Google reviews; including Dr Amit Patel, admitted to BBC journalists that his 4.9 star Google rated practice had outsourced the marketing for Ipswich Spine clinic to a company in India. This led to the chiropractor receiving five-star reviews from a number of bots who had also posted the same reviews at different businesses all around the world, in the same month.

To help get an understanding of the scale of the problem in Britain, the UK government recently commissioned an extensive study of online review services in the country. Alma Economics was tasked by the Department for Business and Trade (DBT) with finding how prevalent fake reviews on third-party e-commerce websites were, as well as how they impacted consumer behaviour, and what harm this was causing – before examining how effective non-regulatory interventions might be in preventing further issues.

To undertake this task, Alma built a machine learning model that was trained on a dataset of known fake reviews. By subsequently applying the trained model on a dataset of 2.1 million product reviews across 9 popular UK e-commerce platforms, the researchers were able to estimate the percentage of product reviews on these platforms that were fake.

To determine what effect fake reviews were having on consumers when they made purchases online, Alma then asked nearly 5,000 participants take part in an experiment that was built by its internal developer team. The online shopping task saw participants who were all familiar with shopping online asked to choose between three items to purchase, based on the information that Alma presented to them.

Embedded in the evidence presented were some poorly written and well-written fake reviews, as well as a number of genuine product reviews. Some participants also had a “warning” textbox which primed them to expect that steps had been taken to moderate misleading content – including reviews.

The impacts of the reviews varied – poorly written fake reviews actually seemed to hurt chances of a product being purchased, with likelihood of it being bought falling by 5.3%. In contrast, well-written fake reviews increased the likelihood that a product would be purchased by 3.1%. Alma concluded from this that fake reviews could be causing between £50 million and £312 million in total harm to UK consumers.

Challenging that through non-regulatory intervention alone may be tough, though. informing consumers that steps had been taken to moderate misleading content on the platform did not impact consumer purchasing behaviour – suggesting that consumer trust in product reviews may be difficult to alter – and that the minimal warnings found on e-commerce platforms at present may not be going far enough.