This paper examines the division of labor between regular workers and non-regular workers on the basis of transaction cost economics. In order to organize human resources in different employment modes efficiently, managers should consider saving of transaction costs not only in the vertical division of labor depending on the human-resource characteristics, but also in the horizontal division of labor depending on the job characteristics. The analysis of the research data based on the division of labor model between regular workers and non-regular workers we built in this paper first shows that there is “boundary of the organization” separating the job assignments for two kinds of the workers; second shows that two balanced-treatment styles of “externalization” and “internalization” can be typified; and finally shows that the attitudes of non-regular workers affect on the effectiveness of the balanced-treatment.
