NGOs are popularly viewed as altruistic and responsive to the needy. However, the availability of donors is a primary trigger for the formation of NGOs. This finding need not dispel the impression that NGOs are altruistic enterprises, though altruism is primarily an individual-level characteristic, but when it leads to the formation of an NGO, the organization will usually require funding, and donors appear to use the existence of other NGOs as a heuristic indicating the need for more NGOs. Thus, the (...) number of NGOs formed in an area is an ecological-level characteristic that may create the impression of self-interestedness, but one that is not necessarily inconsistent with the altruism of the individuals involved. (shrink)