In Monday’s column, I wrote about how putting spare change back into circulation - instead of keeping all that copper and zinc and other metals laying around the house, forgotten - can be a good thing.

Never mind that it was the for-profit coin-counting service, Constar, making the assertions.

My research led me to a wonderful New Yorker article about pennies  that I’d like to share.

It’s as delightful as it is fascinating.

One of the things that tickled me was that reporter David Owen calculated the actual value of picking up a penny from the sidewalk: “Breaking stride to pick up a penny, if it takes more than 6.15 seconds, pays less than the federal minimum wage.”

And here’s Owen’s take on spare change:

“During the past thirty years, the U.S. Mint has produced something like a half trillion coins, most of them cents, yet the Mint estimates that only about three hundred billion coins are currently in circulation. This estimate is probably high, since it includes coins that haven’t budged from their coffee cans in years. Even so, the missing change is worth billions. Where is it? Except in rare cases, old coins, unlike old banknotes, aren’t withdrawn from circulation by the Federal Reserve. People simply mislay them, eventually, in one way or another, and in most cases they disappear as permanently as if they had been dropped into the sea. Pocket change leaks from the economy the way air leaks from a balloon, and most of what leaks is pennies.”

I know a woman who has an annual contest with her nephews. Whomever finds the most currency just in their walks along streets and sidewalks in a given year wins. This year, she’s certain it will be her. Back in January, she found a $20 bill.

Coinstar estimates most households have $90 laying around, although this may include people with collections. I was dubious, and sure enough, in my own search through my house, I found just $27.03.

There were two mini-motherlods: A desktop cup my husband empties his change into, which that day held $7.72. I also remembered a small box into which I’d begun stashing state quarters: $13.75 total. Back into circulation!

Meanwhile, the U.S. Mint has wonderful information on coins, including how many are made and what they are made of.