A contest success function with a tractable noise parameter

I propose a simple contest success function which is a variant of the Tullock probability function under certain conditions. It relaxes two features of the Tullock probability function. I show that this contest success function could be used to obtain interesting results and is more tractable than Tullock's function in certain cases. In particular, researchers who are interested in examining the degree to which luck as opposed to effort affects behavior in different contest settings might find it easier to use this contest success function than the Tullock success function. Unlike the Tullock function, there always exists a pure-strategy equilibrium for all values of the parameter which captures the degree of noise. The proposed function has been used in Kolmar and Wagener (2004) with interesting results.