Which wouldn’t be that big a deal, if women could simply say “no” to such requests.

But while colleagues and bosses seem to understand when a man says no — he must be busy! — additional research has found that if a woman declines small requests at work she is more likely to get worse performance evaluations and fewer recommendations for promotions and is considered less likable by her peers.

Enter the “No Club.”

Yes, it’s a real club, founded by a professor at New York University and two colleagues, to help one another decide when to say “no” and how exactly to phrase those no’s . (Because, let’s not forget, women must be “polite.”)

Dolly Chugh, an associate professor of management and organizations at N.Y.U., who is a member of the group, said that sometimes those no’s mean “this is not worth my time,” while other no’s are part of a negotiation to get to “yes” on more favorable terms. The group also acts as a kind of gut check for when a member might be saying no to something she should actually say yes to.

“We started the club because we tended to feel clear and confident about advice we would give others about when to say no, but were less likely to take that advice ourselves,” Chugh said. “The No Club gives us a confidential place to get that advice and be held accountable for acting on it.”

Babcock, who is an expert in negotiation, has her own group called the “I Just Can’t Say No” club that has expanded into multiple chapters.

And as of today, I’m forming my own — and you’re invited to join it. For the next month, I vow to say no to requests I think are reasonable to decline but would normally say yes to (and then resent the fact that I was doing it). Within reason, of course.

If you’re in, spend the week trying it. (For more tips, see here.) Then email me your best no stories.