The three most famous theories about the selection of expatriates are presented above. Tung’s research is still very valuable today because she is a scholar who began to study this specific area much earlier than other researchers. Mendenhall and Oddou’s frameworks combine the selection criteria with the selection approach, which solves the problems how to test those criteria. As to Ronen’s Model, it assimilates the indispensable predictors of success developed by the former two theories. In other words, it comes down in one continuous line with Tung’s, Mendenhall and Oddou’s frameworks. In addition, Ronen also adds some new elements to develop his model. Therefore, Ronen’s Model is the latest and integrated one to guide MNCs to select the best qualified candidates. It incorporates five kinds of predictors for a successful international assignment.