Pakistan, Aug. 24 -- Every day, millions of Pakistanis buy petrol, groceries, medicines or other everyday necessities and leave their loose change behind. A few rupees may be left on a shop counter, at a petrol station or replaced with a piece of candy, or simply waved away with a casual "it's okay."

Individually, the amount is almost too small to notice. Collectively, it tells a much larger story about how the value of money has changed. Where do our coins actually go? And when did we stop caring enough to ask for them back?

"There was a time when even a few coins had a purpose. We kept them carefully because they could be needed for something at home, and if someone came to the door asking for help, we could give what we had," a 95-ye...