Letters, signs, and colors: How the display of energy-efficiency information influences consumer assessments of products

The increase of energy efficiency is a major goal of many countries throughout the world. For the successful achievement, consumers must choose energy-efficient household appliances. The European Union (EU) has introduced an energy label for energy-related durables to empower consumers to make energy-friendly choices. Due to the great progress in energy efficiency and the ban of inefficient products on the market, only products in the top efficiency classes are available for many categories, while products in lower classes are no longer manufactured. However, the energy-efficiency scale on the label still displays a range of seven classes (e.g., A++-E). This paper presents a systematic analysis of the influence of the presentation format of energy-efficiency information on consumers' assessments of products' energy friendliness. A series of experimental studies reveals that the display of a rating scale that includes only the energy-efficiency classes of products still available in the market (i.e., a shorter scale) enhances consumers' perceptions of the differences in energy friendliness between the classes. Consequently, the findings suggest that the format of the energy-efficiency scale significantly influences consumers' perceptions of the energy-efficiency gains of products in higher efficiency classes, positively affecting their motivation to choose the most energy-efficient products.