What started as a simple holiday marked by small, handmade gestures of love has turned into a multi-billion dollar industry that appears to be driven by the spending of single men trying to find a mate.

A 2013 Harvard Business School study found that single men spend almost three times the amount spent by single women on Valentine’s Day. Married men and women spend significantly less than their single counterparts, despite their usual higher combined income.

College-aged men are expected to spend an average of $104.15 on a partner this holiday.

Nicholls student Johnathan Dent, a culinary sophomore, will be in that number, having to purchase not one but two gifts for his sweetheart.

“On Valentine’s Day, I have to get two gifts because my girlfriend’s birthday is the day before. I feel obligated to get two gifts. I’m planning on getting her a watch,” Dent said.

Jewelry accounts for the majority of Valentine’s spending at almost $4.5 billion annually. It is followed closely by spending an evening out, which accounts for $4 billion each year. Add in the candy, flowers, gift cards and other treats, and you’ll find Americans will have spent a whopping $18.6 billion on the holiday this year.

Why all the expensive gifts, and why are unmarried men doing the bulk of the spending? Michael Norton, the Harvard business professor who completed the study, said it is because single guys “are trying to signal their wealth to prospective partners.” Norton also found that spending money made the giver feel “wealthy,” and therefore led to greater happiness.

Norton found married men, on the other hand, spend significantly less, possibly because “they have already sealed the deal.” Married women spend the least, averaging only about $20 per purchase.

One thing that is clear is that Valentine’s Day is substantially more important to women than to men. Not only did Norton’s study find that men did the majority of the spending, it also found that 14 percent of women would resort to sending flowers to themselves in the absence of a significant other. More than half of women said they would end their relationship if their partner did not splurge on a gift.

Edna Lutterodt, culinary freshman from Kenner, said, “Valentine’s Day is more important to women because we want to feel loved by the guy. Basically, we just want to have a good time on Valentines Day.”

From the male perspective, Shane Paul, computer information system sophomore from Kenner, said “Women like it because they’re emotional.”

Outside of the United States, the focus may be somewhat different. Gilson Filho, music senior from Brazil, said, “Valentine’s Day is very important. In my country lots of couples celebrate more often. It’s equally important to men and women.”

Still, others don’t depend on a mate to make Valentine’s Day special. More than $8 billion will be spent on others such as family members, friends and classmates.

“Valentine’s Day is just another day. You don’t necessarily have to get something from a guy. My mom always gets me things. She would always have a card and chocolate,” Johnene Joy, culinary arts senior from Marrero, said.

For some Americans, all you need is a pet to celebrate Valentine’s Day. Pets are pampered to the tune of $815 million.

Historically, both men and women have had a hand in shaping the holiday celebrated by lovers today. The holiday legend of St. Valentine remains somewhat mysterious, with no one single account being considered the accurate story. One legend suggests that St. Valentine was a third Century Roman priest who was put to death for performing marriages for young men and women, the practice of which had been outlawed by Emperor Claudius II so that he would have an army of single soldiers at the ready. Another contends that Valentine was killed for helping Christians escape from Roman prisons. After being imprisoned himself, he supposedly fell in love with his captor’s daughter and wrote her a letter signed “From your Valentine.”

Others believe that the celebration of Valentine’s Day began as an effort to make Christian a pagan fertility festival, Lupercalia, which was celebrated on Feb. 15. The celebration was outlawed by the end of the fifth Century and officially replaced with St. Valentine’s Day on Feb. 14.

Early American celebrations of Valentine’s Day began in the 1700s, marked by the exchange of handmade greetings. Esther Howland, a Massachusetts woman, helped to commercialize the holiday when she started manufacturing and later mass-producing elaborate valentines in the 1840s.

Today, the tradition of gifting “valentines” has developed into the purchase and exchange of nearly 180 million greeting cards each year, fueling an industry that brings in more than $1 billion on this holiday alone. While the majority of greeting card purchasers are women, nearly 85 percent, the men are purchasing higher-ticket items such as flowers, jewelry and candy.

This Valentine’s Day, a holiday typically celebrated in hues of red and pink, may actually be celebrated in shades of grey as E.L. James’s popular literary trilogy hits the big screen. Universal-Focus is projecting the film “Fifty Shades of Grey” will bring in more than $60 million this Valentine’s Day weekend.