Who will win this November’s presidential election? Spirit Halloween—a chain of Halloween-themed stores that have popped up in strip malls in 49 states—thinks it knows. The “science” behind the prediction is simple: Which candidate sells more Halloween masks at its stores?

According to Spirit Halloween, mask sales have accurately predicted the next president in each election since 1996—four contests in a row. Because capitalism is a beautiful thing, the chain has attempted to humorously capitalize on this trend, naming this polling method its “Presidential Index.” In 2008, for example, people bought more Obama masks than McCain masks by 60 percent to 40 percent. In 2004, people bought more Bush masks than Kerry masks (shocker!), 65 percent to 35 percent. Way back in 1996, even before the Lewinsky scandal broke, people were buying Bill Clinton masks like they were going out of style—with the incumbent besting challenger Bob Dole by 71 percent to 29 percent.

“Election years are always exciting times around Spirit Halloween, as our Presidential Index has proven to be a consistent and accurate predictor of the next president for nearly two decades,” CEO and president Steven Silverstein said in an early-September press release announcing a partnership between his company and Rock the Vote. There’s a good chance Silverstein was smiling and winking while providing the quotable line.

So what will happen this year? As of Monday, according to numbers provided by Fleishman-Hillard, the PR firm that represents Spirit Halloween, people have so far purchased more Obama masks than Romney masks, 65 percent to 35 percent. The company plans to update the figures each week until Election Day, November 6.

While it’s hard to argue with such “science,” it makes one wonder how presidential mask sales are faring specifically in swing states like Ohio, Colorado, Iowa, Florida, Nevada, Virginia, North Carolina, and New Hampshire. Unfortunately, the Spirit Halloween Presidential Index isn’t yet advanced enough to make such calculations. Fleishman-Hillard says swing-state mask sales aren’t being tracked, but does note that in 2008, Obama led in every state a Spirit Halloween store called home.