In today’s Publetariat Dispatch, we share findings from a Harvard Business School study about book reviews.
A study of literary critics was recently conducted and the results have been posted at Harvard Business School’s The Working Knowledge journal.

Executive Summary:

The professional critic has long been  heralded as the gold standard for evaluating products and services such  as books, movies, and restaurants. Analyzing hundreds of book reviews  from 40 different newspapers and magazines, Professor Michael Luca and  coauthors Loretti Dobrescu and Alberto Motta investigate the  determinants of professional reviews and then compare these to consumer  reviews from Amazon.com.

Key concepts include:

• The data suggest that  media outlets do not simply seek to isolate high-quality books, but also  to find books that are a good fit for their readers. This is a  potential advantage for professional critics, one that cannot be easily  replicated by consumer reviews.
• Expert ratings are correlated with Amazon ratings, suggesting that  experts and consumers tend to agree in aggregate about the quality of a  book. However, there are systematic differences between these sets of  reviews.
• Relative to consumer reviews, professional critics are less  favorable to first-time authors. This suggests that one potential  advantage of consumer reviews is that they are quicker to identify new  and unknown books.
• Relative to consumer reviews, professional critics are more  favorable to authors who have garnered other attention in the press (as  measured by number of media mentions outside of the review) and who have  won book prizes.

Author Abstract

This paper investigates the determinants of expert reviews in the  book industry. Reviews are determined not only by the quality of the  product, but also by the incentives of the media outlet providing the  review. For example, a media outlet may have the incentive to provide  favorable coverage to certain authors or to slant reviews toward the  horizontal preferences of certain readers.

Empirically, we find that an  author’s connection to the media outlet is related to the outcome of the  review decision. When a book’s author also writes for a media outlet,  that outlet is 25% more likely to review the book relative to other  media outlets, and the resulting ratings are roughly 5% higher. Prima  facie, it is unclear whether media outlets are favoring their own  authors because these are the authors that their readers prefer or  simply because they are trying to collude.

We provide a test to  distinguish between these two potential mechanisms, and present evidence  that this is because of tastes rather than collusion — the effect of  connections is present both for authors who began writing for a media  outlet before and after the book release. We then investigate other  determinants of expert reviews. Relative to consumer reviews, we find  that professional critics are less favorable to first time authors and  more favorable to authors who have garnered other attention in the press  (as measured by number of media mentions outside of the review) and who  have won book prizes.

Read the full text of the paper (in pdf format) here.