Veil-of-Ignorance Reasoning

Most contested allocations quietly tilt toward whoever is deciding. The deciding team is one of the affected parties, and "fair" ends up meaning "fair to us." Veil-of-ignorance reasoning refuses that tilt by removing the one piece of information that drives it: which affected party you are. The durable move is to decide the trade-off as if you had an equal chance of being each affected person, under a decision rule made explicit, and then return to the actual, positioned decision and confront the gap between the two answers. The mechanism is knowledge removal - de-identification plus equiprobable self-placement - not viewpoint enumeration. You do not walk through each party's eyes one at a time; you make a single self-interested choice under uncertainty about whose eyes you will be looking out of. The output is a veiled-decision comparison: the affected parties, the explicit decision rule, the veiled choice, the positioned choice, the named gap and what it reveals, and the final defended position - framed as one input with a known directional push, never as a neutral verdict.

When to Use

• A decision distributes benefit and burden across parties, and the decider's own position is doing silent work - scarce-resource allocation (who gets the ventilator, the headcount, the discount, the latency budget), or a policy or platform call that trades one group's welfare against another's.
• The deciding team is itself one of the affected parties, and the risk is a self-serving call dressed up as fairness.
• An emotionally uncomfortable but defensible trade-off needs to be made publicly justifiable: "this is what I would want for myself if I did not know who I was going to be."
• The contested matter is normative - whose interests count and how much - not an empirical question of which option performs best.

When NOT to Use

• Do not run it without an explicit decision rule behind the veil. The veil does not by itself produce an answer; the rule brought behind it does. An expected-value rule yields average utilitarianism, a maximin rule yields worst-off priority, and lab groups have converged on floor-constrained averaging instead - same veil, different outputs. Running the exercise without stating the rule launders a contested normative choice as "impartiality." This is the central wall.
• Do not veil away morally load-bearing identity. When particular obligations are doing the moral work - promises, fiduciary duties, desert, compensatory claims for past wrongs, special relationships - the stripped identity information is relevant, not bias (Sandel's critique). Flag these cases and stop or scope down; do not impartiality-wash them.
• Do not present the veiled answer as a neutral verdict. The device has a measured directional push toward the aggregate-welfare ("greater good") option. If worst-off protection, rights, or commitments are what the situation demands, the veiled answer is an input to deliberation, not the decision.
• Do not use it as training or a durability fix. Cross-dilemma transfer failed in the research (study 7). It is a per-decision device; run it on the decision at hand or not at all. Claim no lasting impartiality from having run it.
• Do not use it on an empirical question. "Which option maximizes retention" needs analysis, not impartiality. The veil applies only when the contested matter is whose interests count.
• Do not confuse it with walking each stakeholder's perspective. That is think-parallel-perspectives-review (identity-known, one party's eyes at a time, synthesized after). The veil does the opposite with the same party list: it removes identity knowledge and forces one self-interested choice under equiprobability. The research controls show generic and even utilitarian perspective-taking do not reproduce the effect.