What Causes The Strength-Is-Weakness Effect In Coalition Formation: Passive Adoption Or Active Selection Of Self-Serving Allocation Rules?

In coalition formation, bargainers with many resources are often excluded from coalitions (the Strength-is-Weakness effect). Literature suggests this effect is driven by high-resource bargainers using self-serving allocation rules that backfire, as they prefer equity over equality (while low-resource bargainers prefer the opposite). Four studies test (1) whether this is actually the case and (2) whether high-resource bargainers solely consider equitable allocations or whether they consider both equity and equality but actively choose equity as an allocation rule. We find the Strength-is-Weakness effect even when equality rules are made salient, strengthening the idea that the high-resource bargainers actively select equity as their framework for fairness to attempt to maximize their outcomes. The studies, also suggest an additional reason for the exclusion of high-resource bargainers. We find that high-resource bargainers are likely avoided because they are expected to bargain self-servingly, making the low-resource bargainers seek each other out.