Research finds Yelp reviews reveal some restaurant hygiene problems, but they miss others
BALTIMORE, June 24, 2026 – Consumers increasingly rely on online reviews to decide where to eat, but can those reviews replace traditional health inspections? New research published in the INFORMS journal Marketing Science suggests the answer is both “yes” and “no.”
The study, “Consumer Reviews and Regulation: Evidence from New York City Restaurants,” finds that online reviews contain meaningful information about certain restaurant hygiene problems, particularly issues customers can directly experience, such as pests, spoiled food and food temperature violations. However, reviews provide little insight into many less visible sanitation and safety issues routinely monitored by health inspectors.
Researchers Chiara Farronato of Harvard Business School and Georgios Zervas of Boston University analyzed millions of Yelp reviews alongside detailed New York City restaurant inspection records. Their findings show that consumers can often identify and communicate visible hygiene problems through online reviews, creating an additional layer of accountability for restaurants.
“Online reviews can provide valuable information about some aspects of restaurant hygiene, but they cannot fully substitute for government inspections,” said Farronato. “Consumers are good at spotting problems they can see, smell or experience directly, but many important safety issues remain invisible to the public.”
Using machine-learning techniques, the researchers identified specific words and phrases in reviews that were associated with future health code violations. Terms related to pests, illness and food contamination, for instance, were among the strongest indicators of hygiene problems that were later documented by inspectors.
The study also found that consumers pay attention to these signals. Restaurants were less likely to sell out after receiving online reviews that contained strong indications of hygiene concerns.
Perhaps most notably, the research suggests that restaurants themselves tend to respond to the scrutiny created by online reviews. Businesses with greater visibility on review platforms tended to have fewer violations in areas where consumers could readily identify problems and discuss them online.
The findings arrive as policymakers, platforms and consumers increasingly debate whether digital reputation systems can serve some of the functions traditionally performed by government regulation.
“Our results suggest that online reviews and regulation work best as complements rather than substitutes,” said Zervas. “Reviews provide frequent, low-cost information that can help consumers and regulators alike, but they are much more effective at detecting some problems than others.”
The authors noted that regulators could potentially use information from online reviews to help target inspections, while restaurants could use review data to identify operational issues before they become serious compliance problems.
Read the review in full here.
About INFORMS and Marketing Science
INFORMS is the world’s largest association for professionals and students in operations research, AI, analytics, data science and related disciplines, serving as a global authority in advancing cutting-edge practices and fostering an interdisciplinary community of innovation. Marketing Science, a leading journal published by INFORMS, publishes research on quantitative marketing, consumer behavior, pricing, and strategy that informs managerial and policy decisions. INFORMS empowers its community to improve organizational performance and drive data-driven decision-making through its journals, conferences and resources. Learn more at www.informs.org or @informs.
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