ABSTRACTDigital service platforms increasingly present tipping options as preset dollar amounts (e.g., $1,$2,$3) or percentages (e.g., 10%,20%,30%), yet little is known about how these frames shape consumer generosity. Across eight studies, we demonstrate that dollar (vs. percentage) framing increase tips when the suggested dollar amounts perceived numerically smaller than their percentage equivalents. This effect emerges for smaller (vs. larger) bill sizes, currencies with lower (vs. higher) face values, and higher (vs. lower) tip prompts. The effect is robust across presentation format, sharp and round bill amounts, and when both frames are simultaneously present. The effect attenuates with higher currency face values or lower tip prompts and reverses for larger bill sizes. These findings contribute to the research on digital tipping, numerical cognition, and framing by identifying when numerical presentation drives generosity, while offering actionable insights for marketers and digital platform designers operating in today’s multi-billion-dollar service economy.
ABSTRACT
Digital point-of-sale systems often present numerical tip options (e.g., 10%-15%-20%) alongside verbal options to not tip (“No Tip”). Across one field study (N = 1,023) and seven lab experiments (N = 2,574), we show that including a “0%” tip option paradoxically increases tipping. This effect emerges via two pathways: 1) when “0%” replaces the lowest numeric value, tippers avoid selecting it, leading them to choose higher amounts (Studies 1-4); and 2) when ‘0%” is the only option available to not tip, consumers are more likely to tip rather than selecting it, increasing overall tip likelihood (Studies 4-8). Both effects are mediated by social norms and are not explained by anchoring, inattention, or alternative symbolic meanings. The findings demonstrate that “0” carries unique weight in norm-governed contexts, offering new insights into numerical cognition, choice architecture, and tipping behavior, as well as practical implications for service design, consumer welfare, and labor equity.