Abstract:
The EPA has recently adopted more transparent scales to convey fuel-efficiency. However, consumers’ understanding of fuel efficiency and its cost when expressed on different scales is unclear. Expanded scales of fuel use (e.g. over 10,000 miles) lead consumers to perceive greater differences between cars than contracted scales (e.g. fuel use over 1 mile). We provide empirical evidence of scale expansion amplifying differences in attribute values using both constant-multiplication and inverse-ratio (e.g., miles per gallon vs. gallons per ten thousand miles) expansions in a conjoint design. Choice of fuel-efficient cars is systematically impacted by these manipulations. Expanded scales also increase attribute importance weights derived from conjoint partworths. However, these realized changes in importance weights cannot be distinguished from changes in consumers’ internal representations of attribute values, and thus should be interpreted with care. Additionally, we show that expansions are moderated due to diminishing sensitivity.