Imagine it’s the height of the holiday gift buying season and you’re walking with many other shoppers toward the entrance of a major retailer. Above the sound of nearby traffic and tinny holiday music being piped out of the store, you hear the familiar ringing of a Salvation Army bell.

The bell ringer is wearing a flopped over Santa hat. His arm moves rhythmically up and down as he holds the door, wishes everyone “Merry Christmas!” and nods a thank you to the few who drop money into his red kettle.

You walk casually towards him, palming the gold Krugerrand in your pocket. You’ve wrapped it inside a dollar so it won’t attract notice when you make your deposit.

Just ahead of you a woman opens her purse and pulls out a few bills. In the moment it takes her to fold them so they fit into the slot, you move up quickly to be the next in line. As the attendant turns to thank her for her donation, you slip yours into the kettle, and are into the store before anyone notices anything.

Congratulations. You’ve joined the secretive group of givers who each year slip dozens of Krugerrands (worth nearly $1800 at today’s prices) into Salvation Army kettles around the country.

Why do people like to make these kinds of donations anonymously? A study by Vanderbilt University’s Owen Graduate School of Management found that being publicly recognized for a charitable gift diminishes the giver’s feelings of altruism.

Lead researcher Kelly Goldsmith said, “The effect was so strong that it actually makes givers significantly less likely to donate.”

For unusual donations like the gold coins in the red kettles, the extravagance of the gift can act as a vote in support of the Salvation Army’s mission to help all in need. And when mentioned by local media, it serves as a reminder to others to give generously.

As in other areas of your finances, it’s good to have a plan when it comes to giving. And while you should earmark a consistent amount for charity, you can also have a category for “impulse giving,” situations where your heart leads you to make an unplanned donation.

Special giving during the holiday season, especially to charities that assist people in financial hardship, not only helps those in need, but makes the season more joyful and meaningful for the giver.

End-of-year can be a good time to see what you have available for this kind of giving. And if you’re feeling extra generous (and stealthy), you might also try sneaking a Krugerrand into a Salvation Army kettle.

Warm wishes to you and yours for a joy filled holiday season.