If you're a parent, you're familiar with this challenge: children outgrow shoes very quickly. That can become a serious problem for whole communities that are too poor to afford to replace children's shoes often. That's why Kenton Lee invented The Shoe That Grows.
It's a sandal that comes with snaps in the front, back, and sides. It can expand to 5 shoe sizes. The shoes comes in small and large varieties, so two pairs of shoes can meet a child's footwear needs from the ages of 5 to 15.
Because International, the charity which distributes these shoes, has a motto: practical compassion. It appears that they've found a way to exercise precisely that.
-via 123 Inspiration
Look at it this way...
Assume at any moment, each child is wearing one pair of shoes.
Pass those shoes on when they're too small and you'll still only need one pair of shoes per child, only they'll be cheaper to make and less of an investment lost when they wear out.