Men will spend, on average, nearly double what women spend on Valentine's Day (this trend also continues across all demographics for birthdays, anniversaries, engagements, Christmas, etc), Why so much inequality in terms of gift-giving?

It seems women are in for the biggest treat this year. Men will spend nearly double what women plan to spend ($190.53 versus $96.58 on average).

and

Guys plan to spend an average of $108 on their sweethearts this Valentine's Day, twice what women plan to spend on their significant others. Ladies plan to spend only $53, according to a survey by the National Retail Federation.

This doesn't even include the fact that men overwhelmingly pay for most of the costs of dating too. But why? Men overly generously? Women overly cheap? Where's this 'equality' stuff we hear so much about?