Thanks for posting this thought-provoking story.
I am guessing you’ve maybe never shopped at Liddle though, or other European continental supermarket, who charge a kind of fee for the privilege of not returning the cart (It retains a Pound or Euro coin, deposited firstly to “free” the cart).
How the addition of a coin retaining lock mechanism affects the cart return decision process, even generating a new mode of work for some folk is interesting also. I first came across it when travelling “Penniless” myself across Europe, in Southern France, more than thirty years ago; a large supermarket with an abundance of un-returned shopping carts, each retaning a one-Franc coin, abandoned by a shopper, along with the cart.
It didn’t take long for me to realise a little useful income, from returning a number of those abandoned carts every day.
It can even become a kind of profession, where one can politely offer to return a cart, before the shopper has even finished unloading it.
Much more respectable and dignified, to implicitly ask for a Franc, Pound, or Euro coin that might be going spare in the cart, by return of a little labour on the behalf of the prospective donor.
I guess many carts are even deliberately abandoned with that in mind, secure in the knowledge that someone in need of it will appreciate the anonymously donated coin. I know I sometimes do that nowadays myself. What goes around, comes around.
Extending this logic to the general case, the point of your story; rewarding people for “Going out of their way”, obviously makes a differerence.
Paying people to stay at home maybe works?