Shoe leather cost is similar to opportunity cost. It refers to the cost of counteracting inflation by keeping less of your assets in cash. Your strategy would require more trips to the bank and more walking, and incur a cost in the wearing out of the leather in your shoes.
All joking aside, it’s an interesting idea. It highlights how there are all sorts of hidden costs to different strategies. There are hidden costs to using coupons, loyalty cards, frequent flyer miles, managing assets & investments, hiring resources and in general running a business. Let’s look at a few.