Wigglers and the Willing:  A Within-Subject Analysis of Inequality Concerns

People make pro-social choices, yet researchers still lack tools to quantify how much moral wiggle room individuals exploit or how strongly they trade off money against normative principles. We introduce a within-subject design that measures both. We employ three variants of the Modified Dictator Game: a Self-Other allocation, an Other-Other allocation, and a Plausible Deniability allocation. Each variant elicits a switching point x, where higher values signal greater self-interest. Comparing switching points across variants yields the extensive and intensive margins of moral wiggle room, the money-principle trade-off, and a choice-based taxonomy of types requiring no assumptions about utility functions.We run the experiment in Colombia (N=376) and the US (N=274), with conceptual replications in both countries (N=288 and N=353). A sizable share of participants exploit plausible deniability, though not a majority. The intensive margin remains small in dollar terms, especially in the US. The money-principle trade-off is economically meaningful, yet over 40% of subjects keep their allocation unchanged between the Self-Other and Other-Other settings.Our taxonomy classifies between 60 and 90% of subjects into four robust types. The ordering $x(PD)>x(SO)>x(OO) that would characterize our representative agent represents only 8% of subjects. Roughly one-third exhibit x(PD)=x(SO)=x(OO), a deontological pattern that survives the inclusion of filler tasks. The remaining two types split between genuine social preferences and subjects who posture as deontological.