Sure we adore dear Dad, too, but there is something about Mother's Day that makes consumers spend, spend, spend.

The National Retail Federation estimated that in 2007 consumers spent $15.73 billion on Mother's Day, compared with only $9.9 billion for Father's Day.

This year, Mother's Day spending is expected to reach $15.8 billion or $138.63 per person.

So why all the money lavished on Mother's Day gifts as opposed to Father's Day gifts?

According to one theory, there are only so many ties you can buy a man on Father's Day.

Another theory is that it is just cultural.

"My father never gave a damn about Father's Day," said Howard Davidowitz, a New York-based retail consultant. "My mother was more emotional. It just meant more to her. I think women are more sentimental." Others say it is just the level of gratitude toward mothers, who historically have been the primary caregivers, even though fathers today do more of the child-rearing than previous generations of men.

"Historically, women are considered supposedly naturally best suited to rearing children. We have maternal instincts," said Katharine Antolini, history lecturer at West Virginia Wesleyan University. "We get credit when things go well and we get all the blame when things go bad. It reflects a level of gratitude."

So what kind of Mother's Day gifts will consumers get this year?

Here is a breakdown of spending, based on the NRF study.

Jewelry -- $2.7 billion

Special dinner or brunch -- $3 billion

Consumer electronics such as a digital camera and video camera -- $1.2 billion

Flowers -- $2 billion

Clothing and accessories -- $1.4 billion

Personal services gifts such as trip to a favorite spa or salon -- $1.1 billion

Gift cards and gift certificates -- $1.6 billion

Housewares and gardening tools -- $696 million

Greeting cards -- $672 million