Theme 5 — Does it work? The evidence

Noticing, understanding and outcomes are different questions

Packaging labels are often assumed to work as a chain: the mark is noticed, understood, used, and then produces a better environmental outcome. Evidence at one stage does not prove the next. A consumer who recognises a logo when shown it has not necessarily looked at it on the shelf. A correct answer in a survey is not the same as correct disposal at home. A stated preference is not a purchase.

Each article in this section takes one claim and asks what the studies actually measured. It records the design, the sample, the outcome, the size of the effect, and the main limits on what can be inferred. A laboratory experiment, a field trial, a physical audit and a self-report survey are not treated as equivalent merely because they point the same way.

The section also records gaps. Where a common policy claim has not been tested directly, the article says so, rather than stretching nearby evidence to cover it. The aim is not a single verdict on labelling. It is to show which effects are supported, under what conditions, and how often they have been replicated.