American men are planning to spend $108.38 for Valentine’s Day this year. The most popular gifts will be greeting cards–given by 51% of people–followed by candy at 49%, flowers 37%, and going out to dinner 37%. (The numbers add up to more than 100% because people give multiple gifts).

At first glance, the statistics are unsurprising. You’re thinking, of course people give cards, flowers, chocolates, and go out to dinner on Valentine’s Day. Did they really need to do a survey to find out something so obvious?

But think about from first principles, and the nature of the gifts is puzzling. Out of all the gifts, only one of them has historical significance: greeting cards. According to history.com, Valentine’s Day has long been associated with writing romantic notes, dating all the way back to the Middle Ages. In the 1900s printed cards began to replace the written note, a custom that lead to the estimated 1 billion Valentine’s Day cards that are now sent out each year, second only to Christmas in popularity.

Okay, so greeting cards are a long-established tradition. What about the other gifts? Even if you spend $10 on greeting cards, that still leaves about $100 that you can spend on other gifts. You can buy a lot of nice things with that kind of money, like a necklace or ear rings, perfume, wine glasses, or a romantic movie.

Why instead do people overwhelmingly opt for chocolates, flowers, and going out to dinner?

The answer has to do with game theory. As argued below, these gifts make perfect sense given the statistics of dating and relationships. More precisely, gifts like chocolates, flowers, and going out to dinner are part of a subgame perfect equilibrium for a stylized Valentine’s Day gift game. Let’s see why.

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"All will be well if you use your mind for your decisions, and mind only your decisions." Since 2007, I have devoted my life to sharing the joy of game theory and mathematics. MindYourDecisions now has over 1,000 free articles with no ads thanks to community support! Help out and get early access to posts with a pledge on Patreon. .

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The trust game of gifts

We will model the situation of gifting in the following stylized game.

Bob is thinking about getting a gift for his significant other Alice. On the one hand, Bob can give “experience” or “consumable” gifts that are immediately enjoyable, like chocolate, flowers, and going out to dinner. Alice is very likely to enjoy these gifts, and he enjoys that she is happy, so both receive a payoff of 1 point.

On the other hand, Bob can give a “material” or “durable” gifts that last over months or years, like jewelry, clothing, or a new cell phone. If Alice chooses to stay in the relationship for another year, then the gifts are excellent and both receive a payoff of 2. If she breaks it off, however, then it is bad for both. Bob has spent a lot of money, and Alice feels the gifts remind her of Bob and does not enjoy them. They both get a payoff of -1.

Here is a game tree that summarizes the situation.

What can we say about the game? Will Bob give an experience gift or will he prefer the material good?

Solving the gift game

What Bob does clearly depends on what he believes Alice will do. There are two possible ways this game can play out.

Case 1: If Alice is going to stay in the relationship, then he’s going to want to gift a material good, for a payoff of 2, rather than the experience gift that gives a payoff of 1.

Case 2: If Alice is going break off the relationship in the upcoming year, then Bob would rather spend money on an immediately enjoyable experience.

(Technically if Alice is maximizing her utility, she does better to stay in the relationship (2) than to break it off (-1). However, in this game, imagine she is better off breaking it off–that is, she swallows a bitter pill now (-1) for a prospect of higher payoffs in a continuation game).

These are the two possible ways the game could play out (in game theory jargon these are subgame perfect equilibria, as each person is playing the smart action with correct beliefs about what the other will do.)

The actual way the game plays out depends critically on one factor: Bob’s belief about whether Alice will stay with him.

Does Bob trust Alice?

If Bob could read Alice’s mind and see the future, he would know exactly the correct choice to make. Of course no one has this kind of clairvoyance so Bob has to settle for making an educated guess.

We can model the situation as follows: Bob has a belief that Alice is the type of person that will stay in the relationship. In game theory, beliefs are modeled as probability distributions over actions. So we can write that Bob thinks there is probability p that Alice will stay with him, and the complement event that Alice breaks it off happens with probability 1 – p.

We can now model Bob’s decision in terms of an expected payoff and it is reasonable that Bob will wish to maximize his expected payoff. So we now compare the payoffs for giving an experience gift versus giving a material gift.

The experience gift is easy: Bob is going to get a payoff of 1 guaranteed.

E(experience gift) = 1

The material good is not too much harder. With probability p, Alice stays in the relationship and Bob gets a payoff of 2. So the expected payoff to that is the product of the probability and the payoff, which is 2p. With probability 1 – p, Alice breaks it off and Bob gets a payoff of -1. This is an expected payoff of -(1 – p). We now add those two expected payoffs together for the expected payoff of giving a material gift. That is,

E(material gift) = 2p + -(1 – p) E(material gift) = 3p – 1

Bob now compares the payoff for the choices of an experience good and the material good. He is better off giving the material good only if the following equation holds.

E(material gift) ≥ E(experience gift) 3p – 1 ≥ 1 p ≥ 2/3

This solution makes sense intuitively. Bob is better off giving the material good only if Alice is likely to stay with him. This stylized version indicates that Bob should only give a material gift if he thinks there’s better than a 2/3 chance Alice will stay with him over the year.

If Bob is uncertain of their future together, he would rather give something they can both enjoy during Valentine’s Day–a safe and low risk gift combination along the lines of chocolates, flowers, and going out to dinner.

Statistics of relationships

It is not simple to estimate the number of relationships that end in a breakup. One author Hellen Chen estimates that 85% of couples dating end up in a breakup.

The outlook is better for committed couples. But in America, current estimates are about half of first marriages end up in a divorce.

Attitudes on gift-giving

The statistics imply that men would be more likely to give experience gifts–they can provide a good memory even if the relationship doesn’t work out. (As in Casablanca, “We’ll always have Paris.”)

Furthermore, there is some evidence that people actually do think about gifts strategically. There is a very interesting study published in Advances in Consumer Research from 1991 that explored attitudes students at the University of Utah. It’s called Can’t Buy Me Love: Dating, Money, and Gifts by Russell W. Belk and Gregory S. Coon. It’s long but definitely very interesting and worth a read.

The relevant part for this discussion is how men and women perceive gift-giving. The fairytale version of romance is that couples exchange thoughtful and expensive gifts to show how much they love each other. The reality is that couples are much more critical and strategic in the kinds of gifts they choose.

One 22-year old male is thinking exactly along the lines of the subgame perfect equilibrium of the game described above.

I’m not a big gift giver because giving gifts is too dangerous I don’t like giving serious gifts. The last thing that you want to do is to give a gift that ties you up. There are two things to keep in mind before you give a gift — what happens when you break up? You don’t want to give a present that your old girlfriend is going to want to throw away because it reminds her of you. And you definitely don’t want to give her something that you are going to want back if things don’t work out. Food is the best gift that you can give or get. After all how threatening can a cake be?

Valentine’s Day Gifts

And that brings us back to Valentine’s Day, a holiday where typically men are expected to show their romance with a variety of gifts. What gifts make the most sense in this situation?

Something like jewelry can be a risky gift: if the relationship ends, the girlfriend may not even enjoy using it. Same thing goes for clothes, a new cell phone, or any other durable type product.

The gifts that make the most sense are ones that are still expensive, but they are consumable and readily appreciated as part of the experience: chocolates, flowers, and going out to a nice dinner.

That men give strategically smart gifts is an interesting observation. As for the question of whether Valentine’s Day itself as a tradition makes any sense, that’s one I leave for you figure out.