Seen through a window, (from left) hosts Ainsley Earhardt, Brian Kilmeade, and Steve Doocy broadcast Fox and Friends from the Fox News studios on February 17th, 2017, in New York City. (Photo: Drew Angerer/Getty Images)

When an election is very close—such as the 2016 presidential contest, in which 80,000 people living in three states gave Donald Trump an Electoral College win—seemingly small things can make an enormous difference. Here's one you probably hadn't thought of: where the Fox News Channel happens to fall on your cable provider's line-up.

A study published in the September issue of the American Economic Review finds people are more likely to tune in to Fox News, however briefly, when it happens to fall lower on their channel line-up (Channel 12, say, as opposed to Channel 72). And even a bit more time watching Fox News increases the odds you'll vote for the Republican candidate for president.

"If a viewer is looking for news, and Fox News happens to be the first news channel they flip to, they may watch Fox News because of that fact," said political scientist Gregory Martin of Emory University, who authored the paper with economist Ali Yurukoglu of Stanford University.

"We estimate that cable news can increase polarization and explain about two-thirds of the increase among the public in the United States."

And even brief exposure to Fox's extremely partisan worldview can influence people who consider themselves moderates, or lack strong political beliefs. That's what the researchers found when they compared cable channel line-ups in a given zip code with voting records and survey data for the 2000, 2004, and 2008 presidential elections.

"Watching an extra 2.5 minutes per week of Fox News in an area where Fox has a low channel position is associated with a 0.3 percent increase in the probability that a viewer in that area will vote for the Republican candidate in the presidential election," Martin concluded.

Given how few persuadable voters exist in today's political environment, influencing the votes of three out of 1,000 people is no small matter.

Importantly, the researchers found no evidence that Fox News was on lower channels in Republican-leaning districts. Rather, their analysis found its placement was basically random.

Previous research on the Fox News effect found communities that had access to the channel in 2000 voted in larger numbers for Republican presidential candidate George W. Bush. Martin and Yurukoglu's analysis suggests that impact only increased for the next two presidential elections.

"We estimate that cable news can increase polarization," they conclude, "and explain about two-thirds of the increase among the public in the United States."

Thanks, Rupert Murdoch!

That said, this research suggests Fox's political power may have peaked. "Fox News Channel is already close to achieving the maximal Republican vote share it can attain on its own," the researchers write. "Its power consists almost entirely of the damage it could do to Republican candidates by moving to the left."