Multiple Probit Analysis with a Nonzero Background

摘要

The 'EM' (Expectation-Maximization) algorithm is applied to probit analysis with multiple independent variables and a nonzero response rate. The equations for the maximum likelihood estimators are relatively simple, and converge in all the cases so far examined. An animal bioassay example is used to demonstrate the method. Likelihood ratio tests are used for significance tests in the analysis.