Morris, Daniel Kahneman whilst being a heavy weight in his field, is not the only authority. Indeed, Gerd Gergerenzer (his most prominent critic) has argued strongly that Kahneman treats people as being basically incapable of making the best choice for themselves, which Gergerenzer argues isn't actually the case. Kahneman even admitted he relied too heavily on weak studies in some areas of his book (which was a very gracious thing to do when confronted with a criticism of your life's work).
I have always thought that shops be they supermarkets or general stores or anything in between, should provide a price in weight. And many do in many countries, as Dina says it is often the law. People should be able to do their own calculations too, but then again at the end of the day customers just want a good value proposition. Each of us might have a different idea of what that is, but the more information available then the easier that is for consumers to make their own choice, rather than a guided one.
But this is all way off topic. Perhaps we should get back to discussing Peace Talks.
For those that are interested I will be starting a thread in the Bar for anyone who wishes to discuss this all further.
Link:
https://www.paranetonline.com/index.php/topic,53300.0.html