We estimate a system of three behavioral equations for Brazilian children and teenagers (school absenteeism, health status and child labor). We relieved the assumption of independence of the disturbance terms of each equation. Moreover, if causality mechanisms between these three components (school absenteeism, health status and child labor) can occur either way, it can also be the result of a simultaneous decision-making process. Thus, to take into account both endogenous causality aspects and simultaneity, we estimate using the FIML method, which provides some improvement to the quality of the estimation, allowing us to simultaneously estimate all relevant parameters, including covariance parameters, and also to the subsequent interpretation of the results.