Choice of Scale and Asymmetric Logistic Models

Abstract

AbstractIn recent years, a number of authors have proposed generalizations to the binomial logistic model. These proposals were motivated, in part, by the claimed inability of the logistic model to fit asymmetric data, that is, data that does not follow a symmetric S‐shaped curve. In this note, it is demonstrated that by changing the scale of the independent variable(s), the logistic model can fit asymmetric data. Logistic models are fit to data from BLISS (1935) that had been used as an example by three of the authors; the logistic models fit Bliss' data as well as the proposed alternative models. In a general sense, these data serve as an example of the need to consider the appropriate choice of scale of the independent variables in logistic analysis.