Givers set the minimum for a small gift about 70% above what recipients would take

The gap between what givers think is enough and what recipients would take showed up in two separate experiments, at almost the same size. In the car-wash study, givers thought a tip needed to be at least $1.89. The attendants would have accepted $1.09 ^[8]. In the second, participants decided how much of a $10 payment to give someone who had completed a 10-minute task; givers would not go below $3.38 on average, and recipients would have accepted $1.97 ^[9]. The givers' floor sat about 73% above the recipients' in the first case and about 72% above it in the second ^[16][17].

The authors put the gap down to appearances. They argue that people holding only a quarter worried a token tip would send the wrong signal ^[14]. The concealment result fits that account ^[6]. Jean Zhang, who led the paper, "Give Enough or Not at All," in the Journal of Economic Behavior and Organization ^[3], did the work during her PhD at UC San Diego ^[15]. "Businesses and organizations can make small acts feel legitimate. Show that they count, and that they add up to meaningful progress," she said ^[11].

All four studies, which involved nearly 2,000 people, concerned giving money ^[4][12]. The researchers suspect the pattern extends to other areas, and Wharton's write-up of the work calls that a question for future research ^[12]. A manager who wants more volunteering hours, or more ideas raised in meetings, is extrapolating from tips and donations. I think the signalling account plausibly fits those settings, because a thin contribution made in front of colleagues carries the same risk of looking inadequate. None of the experiments measured it.

The firmest caution comes from a co-author. "In the field study, asking for $1 increased the number of people who donated in a context where a small gift might otherwise have seemed inadequate, but it also shifted donations toward $1 and did not significantly increase the total amount raised," said Gal Smitizsky, a Wharton professor of operations, information and decisions ^[2][3]. He said a small suggested amount can also nudge generous donors toward giving less, and named grouping donors by their past behaviour as the key response ^[13]. "If you know your audience, a smaller ask is a good way to raise participation. But if you're asking people who have given generously before, a higher ask may make more sense," he said ^[10].