Persuasion as a contest

We examine how the probability of persuading an audience depends on resources expended by contending parties. We use a Bayesian approach whereby the audience makes inferences solely based on the evidence produced by the constants. We find conditions that yield the well-known additive contest success functions, including the logit function. We also find conditions that produce a generalized "difference" functional form. In all cases, there are three main determinants of audience choice: (i) the truth and other objective parameters of the environment; (ii) the biases of the audience; and (iii) the resources expended by the interested parties.