The paper investigates the optimal allocation of human resources both theoretically and empirically. The theoretical part shows that some wage compression is desirable for the following two cases; (1) hawks (i.e., uncooperative and aggressive workers) work together, or are in the common work-place, and (2) hawks and doves (i.e., cooperative and less aggressive workers) work together, and seek promotion in the competitive world. The empirical part presents the result for Japan. We find that large Japanese firms had wage compression for younger generations in order to minimize the degree of adverse effort caused by the behavior of hawks. At the same, we try to find, “Who is likely to be hawkish?”