It is often assumed in foodie-heavy cities like New York that a restaurant's fate depends on the opinions of powerful critics like The New York Times's Sam Sifton and New York's Adam Platt. Reuters blogger Felix Salmon, with the help of New York intern Ray Rahman, looked into the question of whether a restaurant's review affected the prices on its menu. It was not quite a scientific study--here's their spreadsheet--but their analysis of restaurants in New York City reviewed by Sifton and Platt found little correlation between positive reviews and price hikes. An quick look at the chart from Salmon above shows that prices fluctuated with little regard to how many stars were awarded by Sifton. The chart for Platt's reviews can be found here.
At the same time, there are certainly exceptions to the rule: the only four-star review Sifton has given was followed by a price hike, and another up-and-coming restaurant in Brooklyn raised its prix fixe menu to $185 from $165 just two days after getting three stars from Sifton. And Salmon's not trying to say that restaurant reviews have no effect on overall business, either: "It's worth noting that a good review is profitable for a restaurateur even if prices stay flat," Salmon says. Here's his takeaway for restaurant-goers: "the lesson here is that price is no particular guide to food quality."