Empirical likelihood confidence regions for the parameters of a two phases nonlinear model with and without missing response data

In this paper, we use the empirical likelihood method to construct the confidence regions for the difference between the parameters of a two-phases nonlinear model. Two-phases nonlinear model with response variables missing at randoms is also studied by proposing three empirical likelihood statistics and it is shown that all this statistics have asymptotically chi-squared distributions. By Monte-Carlo simulations we show the performance of the proposed test statistics.