"It's been estimated that $800 or $900 million is lost in business on this day because people will not fly or do business they would normally do," said Donald Dossey, founder of the Stress Management Center and Phobia Institute in Asheville, North Carolina.
Among other services, Dossey's organization counsels clients on how to overcome fear of Friday the 13th, a phobia that he estimates afflicts 17 to 21 million people in the United States.
Symptoms range from mild anxiety to full-blown panic attacks. The latter may cause people to reshuffle schedules or miss an entire day's work.
When it comes to bad luck of any kind, Richard Wiseman—a psychologist at the University of Hertfordshire in Hatfield, England—found that people who consider themselves unlucky are more likely to believe in superstitions associated with bad luck.
"Their beliefs and behavior are likely to be part of a much bigger worldview," he said. "They will believe that luck is a magical force and that it can ruin their lives."
Wiseman found that one quarter of the 2,068 people questioned in a 2003 survey associate the number 13 with bad luck. People with such feelings, he found, are more likely to be anxious on days like Friday the 13th and thus more prone to have accidents. In other words, being afraid of Friday the 13th could be their undoing.
So how did Friday the 13th become such an unlucky day?
Dossey, also a folklore historian and author of Holiday Folklore, Phobias and Fun, said fear of Friday the 13th is rooted in ancient, separate bad-luck associations with the number 13 and the day Friday. The two unlucky entities ultimately combined to make one super unlucky day.
Dossey traces the fear of 13 to a Norse myth about 12 gods having a dinner party at Valhalla, their heaven. In walked the uninvited 13th guest, the mischievous Loki. Once there, Loki arranged for Hoder, the blind god of darkness, to shoot Balder the Beautiful, the god of joy and gladness, with a mistletoe-tipped arrow.
"Balder died and the whole Earth got dark. The whole Earth mourned. It was a bad, unlucky day," said Dossey. From that moment on, the number 13 has been considered ominous and foreboding.
So to celebrate, let's all stop by and rent "Friday the 13th" and make a date with Jason Voorhees at Camp Crystal Lake tonight! Happy Triskaidekaphobia Day!