  Empirical phi-divergence test-statistics have demostrated to be a useful
technique for the simple null hypothesis to improve the finite sample behaviour
of the classical likelihood ratio test-statistic, as well asfor model
misspecification problems, in both cases for the one population problem. This
paper introduces this methodology for two sample problems. A simulation study
illustrates situations in which the new test-statistics become a competitive
tool with respect to the classical z-test and the likelihood ratio
test-statistic.
