Are All Units Created Equal? The Effect of Default Units on Product Evaluations

Previous research on attribute framing has shown that people often infer higher quantity from larger numbers, usually with the assumption that the units used to specify this information elicit the same meanings. Drawing on literature on categorization and numerical cognition, the authors challenge this assumption and show that consumers often have preset units for attribute levels that strike an optimal balance between a preference for small numbers and the need for accuracy (study 1a). As such, these default units appear commonly (study 1b). Specifying positive attributes in default units renders products’ evaluation more favorable, even if such specification lowers the nominal value of the attributes (studies 2–4). This effect disappears if participants attribute metacognitive feelings generated by default units to an irrelevant source (study 3). Study 5 shows that a default unit effect is more likely in single evaluation mode, but a numerosity effect may reemerge in joint evaluations.