What I understand is this: Even if a merchant wants to do it, they are going to alienate customers if they are the only one doing it, they are going to have customers telling them they don't like it, and so the merchant will stop doing it. For this to become standard practice, it must be required by regulation, one way or another. Transparency does not always emerge naturally from the market, and it is often necessary to coordinate everyone by adopting regulations.
Would you be in favour of taking the discussion in that direction? I do not have a specific proposal at the moment but could we move the discussion in that direction? I ask these questions because the natural equilibrium seems to be taking us somewhere where virtually no retailers are including this information on the bill, even if they are entitled to do so.