Suppose you need to decide whether to make or not a donation to National Public Radio (NPR). To simplify the analysis, assume that donations are the same fix amount (C = 10) for everybody who decides to donate, and that private contributions are the only source of funding for the radio. The variety of programs that NPR is able to supply and therefore the utility of listeners depends on the number of individuals donating. If n individuals donated to NPR, the benefit of listening to the radio for those who donated is B(n) = 2n 58, and 4n for those who did not donate