["Business Strategy and the Environment, EarlyView. ", "\nABSTRACT\nAs global environmental concerns intensify, firms are increasingly expected to embed environmental responsibility into their core strategies. However, uncertainty remains over whether eco‐friendly initiatives are economically rewarded, reflecting ambiguity in consumers' true environmental preferences. Although consumers frequently express positive intentions towards eco‐friendly products, these rarely translate into actual purchases—an issue known as the intention–behaviour gap. This study empirically examines the psychological mechanisms underlying this gap using data from a 2024 survey undertaken in Japan, Germany, China and the United States. Cross‐national partial least squares structural equation modelling reveals that while both altruistic and self‐interested motives shape purchase intentions, self‐interest largely constrains willingness to pay. Providing clear, specific information about environmental and consumer benefits narrows the intention–behaviour gap, especially for recycled and plant‐based plastics. These findings show that effective marketing must appeal to consumers' self‐interest through functionality and reliability while reinforcing environmental value with credible, transparent communication.\n"]