A protest need not be a huge affair to have an impact on a company's bottom line, according to a new study co-authored by a Brigham Young University professor.

In fact, the analysis of nearly 30 years of protests found that what matters most is not the number of sign-waving participants but the amount of media coverage the event received.

Of the 342 protests covered by the New York Times between 1962 and 1990, stock prices of the targeted companies fell one-tenth of a percent for every paragraph printed about the event, the analysis concluded.

"We find that the size of the protest actually doesn't matter at all," said lead author Brayden King, an assistant professor of sociology at BYU. "You can have a very small protest with a lot of media coverage and do more damage to the company's image than a large protest with a lot of participants."

The study, which will soon be published in the academic journal Administrative Science Quarterly, found that protests caused an average decline in stock prices between 0.4 percent and 1 percent. The drops usually took place on the day of the protest or the day after, and prices tended to return to expected levels about five days after the event.

"It's a fairly quick decline, but even that kind of a quick decline can lead to a noticeable loss of investment capital," said King, whose co-author was Sarah Soule of Cornell University.

The dip in stock prices can happen for a number of reasons, including fears that the media coverage will hurt the targeted company's brand image or reputation.

"Fundamentally, investors react negatively to some sort of announcement or event because there is a fear or perception that there will be a decline in the net present value in the company," he said.

Sometimes, however, the impact is more long-lasting. A very public 1992 protest after Cracker Barrel instituted a formal policy against hiring homosexual employees resulted in a 26 percent drop in stock prices against the restaurant chain, the study notes.

"One message that comes from this is the guy on the street can exert some power and influence on big corporations," King said. "The key thing here is finding an ally in the media."

E-mail: awelling@desnews.com