Does category reporting increase donations to charity? A signalling game approach

Many charities report donations using categories. We question whether such category reporting increases donations in a signalling game where a donor is either generous or not generous. Conditions are derived under which category reporting will increase giving or decrease giving. Category reporting will increase giving if the probability a donor is generous is low and/or donor preferences depend a lot on type. Category reporting will decrease giving if the probability a donor is generous is high and/or donor preferences depend little on type.