In estimation (I) in table 4, we include those variables with only a complete set of observations in order to maximize the sample size and hence the robustness of our results. This estimation captures the relation between infant mortality and its determinants for children born between January 1971 and September 2007. In estimation (II) in table 4, we use the same set of variables, but include only the children that were born during the 10-year period prior to the survey, thereby reducing the sample size by about one half (from 41,153 to 19,146).