The kind of gift you receive from your sweetheart this Valentine's Day will depend upon how soon he or she starts shopping for you, according to a new study.

Researchers from Stanford, Berkeley and the University of Chicago have shown that early bird shoppers, who start purchasing gifts a month in advance, will get a grand present to dazzle their beloveds, while late shoppers, who start their gift hunting just the night before, will get a present that merely won't disappoint their partners.

Cassie Theriault of Stanford University says that when the gift-giving deadline approaches, our perspective shifts from gifts with positive outcomes, something that will knock your sweetheart off his or her feet, to gifts that will simply help us avoid a fight.

"Consumers facing an imminent decision are confronted with the negative possibility of failing to fulfill their purchasing goal," said Theriault (Stanford University), Jennifer L Aaker (University of California, Berkeley), and Ginger L Pennington (University of Chicago).

"When the purchase is still far off in the future, however, consumers are likely to be fairly optimistic about succeeding and less concerned with the possibility of goal failure," they added.

The researchers conducted a series of consumer behaviour experiments, including one involving 101 university students asked to book either a last-minute summer vacation or an upcoming winter holiday though a fictitious website.

The sites ran negative ads that read, "Don't get stuck at home!" and "Don't get ripped off" as well as positive ads that read, "Give yourself a memorable vacation!"

Participants arranging the last-minute trip were prepared to pay on average 178 dollars more for a vacation when the site flashed negative ads as compared with when positive ads were shown on the site.

Meanwhile, participants planning the winter vacation said they would pay an average of 165 pounds more for a holiday when faced with the positive ads over the negative.

The researchers suggest these findings shed light on how the anticipation of pain and pleasure affect the way consumers make purchasing decisions. Consumers are particularly receptive to negative advertising when pressed for time and heavily influenced by positive advertising when doing long-term planning.

Theriault suggests consumers constantly negotiate long- and short-term considerations in their daily lives for everything from car shopping to dieting.

The study says the findings may also demonstrate connections between impulse decisions and will power. The conflict between short- and long-term goals can be an emotional influence in the decision-making process, the authors noted.

"Off in the distance, consumers may focus on the desire to be svelte, anticipating the pleasure from being slender," the authors said.

"However, when the choice is immediately upon them, the more minimal goal of not looking fat seems more attainable. Thus, the anticipated pleasure associated with being svelte may begin to wane, and the anticipated pain associated with becoming fat may start to feel particularly threatening," they added.