While we distinguish the first four 'rungs' of the Intervention Ladder as involving different degrees of organisational involvement and (potentially) cost, we do not distinguish them on ethical grounds: all are 'altruist-focused interventions'. We do not consider that refunding expenses involved in donation or providing minor tokens as a „spur‟ to donation involve ethical compromises in a way that information campaigns or letters of thanks do not. Thus the rationale for deciding between these four rungs will effectively be empirical: is it necessary to advance a 'rung' to ensure that people who are potentially willing to donate.
