Another shopper and I approached two unoccupied cashiers simultaneously. The decision about who transacted with whom seemed arbitrary and was settled nearly instantaneously without verbal exchange. I went left, she went right. But seconds later I realized we’d made a mistake.
I was pushing a wide, double stroller with a sleeping toddler as cargo (Fraktion freight of a different sort?). A support column in the center of the left checkout aisle I selected prevented my entry. Heroic contortions of the over-sized stroller might have permitted passage but would have risked waking the toddler. I know well the opportunity cost of a ruined nap so I kept the stroller steady and took the only checkout option available to me.
Thus, I moved from the left to the right cashier and was now in line behind the other shopper who could have used either checkout (she was pushing a relatively narrow shopping cart, not a double-wide stroller). The checkout I vacated was now empty with an idle cashier. Clearly I would have been better off if we had made the opposite assignment of cashiers to shoppers. At the moment I had this thought it wasn’t too late to do so as the other shopper had not yet removed any items from her cart.
A Pareto improving change in the allocation of cashiers to shoppers was possible! That is, I would be better off if the other shopper and I switched, she to the left and me to the right cashier. She would be no worse off. In fact, I could compensate her for making the change. How much were the few minutes of time saved by making the switch worth to me? A quarter? A dime? How much would she require to spend ten seconds switching? A nickle? A penny? This market should clear. But it didn’t.
That’s because we don’t normally think this way. It’s a little weird. Knowing as much I would not (and did not) offer her cash to switch. The most I would have done is politely point out that I was unable to use the other cashier and ask if she would mind changing. But I didn’t even do that. And the reason is that I was enjoying the thoughts I just shared.
With a sleeping child in the stroller and a rare quiet moment in a busy weekend my mind went into economist mode. I had a good time and would not have traded the experience for even a dollar. Paradoxically the allocation of cashier resources to shoppers turned out to be efficient after all. My delay provided an opportunity to think about its inefficiency, turning the loss into a gain. Moreover, the opportunity cost of a toddler’s blown nap has been revealed. As she slept my mind was free to compose this post. I typed it up later as the well-rested and happy child enjoyed the stickers and crayons that I had purchased during the shopping trip through which she had slept. Some things even (or especially) an incidental economist cannot improve.