Humanization promotes equality over efficiency preference in carbon allocation

Decisions regarding international carbon allocation present an efficiency–equality dilemma. In addition to serving national interests, recent studies have shown the moral value foundations of carbon allocation preferences. Nevertheless, concentrating only on the moral values of the allocator is insufficient; the allocator's moral concern for the allocatees often plays an equally or even more crucial role. Inspired by the moral concern model of humanization, we propose that the humanization of allocatees boosts empathy toward them, thereby promoting equality (versus efficiency) preference in carbon allocation. The results of three studies (N = 911) reveal that humanization increases selection of more equal (versus efficient) allocation proposals (Studies 1–3) and decreases credit allocation differences between allocatees (Studies 2 and 3). Further, enhanced empathy is found to mediate these effects (Studies 2 and 3). By identifying the roles of humanization and empathy in carbon allocation preferences, this research provides a moral concern framework for understanding international carbon allocation controversies and has important implications for promoting climate governance cooperation.