Perceived human and material costs of disasters as drivers of donations

Are disaster relief appeals more successful if they emphasize the material cost of disaster events in terms of economic damages and need for shelter, food, and health care, or if they emphasize the human cost in terms of psychological suffering and trauma caused? Although giving patterns seem to suggest that large-scale events that cause widespread material damage (e.g., the Asian Tsunami of 2004) are more successful at eliciting donations than...