Research shows that 'trust' is the central element in the decision to give.
I have copies of the two reports which were commissioned by the two agencies for which I was working at the time. The research has never been published, although the agencies did approve of general details being disclosed at an Australian fundraising conference some years ago. To publish the material in detail, I would need to get their approval. The research was qualitative and did not attempt to rank the factors in order of importance, rather tried to pick up recurrent themes from the free flowing conversations within the focus groups. I think it likely that participants did make subconscience value judgements based on the impressions they had of relative urgency amongst other things.