As couples look forward to Valentine’s Day as a time to celebrate love and togetherness, retailers have their own cause for celebration: The average American plans to spend about $130 on Valentine’s Day gifts this year, and total spending will reach a record $18.6 billion, according to a survey by the National Retail Federation.

But while the holiday provides a seasonal boost to purveyors of roses, greeting cards, and chocolates, marketers are more interested in understanding the factors couples consider as they make bigger purchases together throughout the rest of the year.

For many spouses, shopping for items such as cars and televisions is a joint activity. Even in a healthy relationship, partners can clash about what they do or don’t want to buy. The husband may have a price he doesn’t want to exceed, while the wife may hate a particular brand. The goal is to find a product that makes everyone happy, but in some cases the conversation just reaches a sticking point.

For example, if the husband doesn’t want a Sony TV but the wife wants Sony to remain an option, someone will eventually have to concede. In an interview with Texas Enterprise last year, Ty Henderson, assistant professor of marketing at McCombs, discussed his research about how married couples adjust when their product preferences conflict:

“The husband has his preferences for the product attributes, and the wife has her preferences. The give-and-take of a joint decision gets interesting when must-have and can’t-have attributes are involved.”

Henderson explored this scenario in a 2011 study, finding that when a couple agrees to narrow down the options as much as possible, they are more likely to be satisfied with their eventual purchase and less likely to feel regret. So in the TV example, the best course of action would be to exclude the Sony products, which only one person in the couple would truly appreciate.

“When we both agree to kick out certain brands, we make faster decisions, we have to compromise less and we make more efficient decisions.”

So how can you use this information? Henderson says that going along with your spouse’s “must-have” or “can’t-have” decision criteria might make for a better decision rather than convincing the other person to seriously consider a brand or attribute he or she doesn’t really want.

“In the end of course, bear in mind that citing academic research doesn’t always help you win an argument at Best Buy. But it might help.”