Surprisingly unsustainable: How and when hindsight biases shape consumer evaluations of unsustainable and sustainable products

Sustainability as a vital purchase criterion in sustainable consumption contexts is often biased by misguided information. In this context, we investigate the hindsight bias, i.e., consumers think in hindsight that they knew what would happen all along, may lead consumers to think they evaluated attributes of unsustainable or sustainable products correctly all the time while they did not, devaluating downstream marketing variables. This paper experimentally investigates the hindsight bias by manipulating information about a products' sustainability. We focus on two perspectives about hindsight biases, namely, marketing and psychology, to explore the interaction of surprise and sustainability. In a set of two online studies (Study 1: n = 300; Study 2: n = 461), we found a group‐based hindsight bias for high‐involvement, unsustainable products (Study 1) and individual hindsight biases for low‐involvement, unsustainable and sustainable products (Study 2). Contributing to both, mostly separately researched perspectives, we conclude that neither is predominantly correct. Instead, both perspectives jointly determine why consumers evaluate products differently. Confronted with surprising, sustainable information about unsustainable products causes a hindsight bias that increases purchase intention and word of mouth. In contrast, surprising, unsustainable information about sustainable products show opposed effects. Implications for marketing practice show when product information can unintentionally cause greenwashing and how product information should be communicated to underline a product's sustainability.