This paper uses panel analysis to assess the relationship between unions and ratios of direct and indirect nonstandard employment using both balanced and unbalanced panel samples from the four waves of the Workplace Panel Survey provided by the Korea Labor Institute. Both balanced and unbalanced panel samples revealed an inverted U-shaped relationship between the ratio of directly-employed nonstandard workers and unionization rate, and a U-shaped relationship between the ratio of indirectly-employed workers and unionization rate. In the former case, the inverted U-shaped relationship that the ratio of directly-employed nonstandard workers initially increased, followed by a decrease as the unionization rate reached a certain point. On the other hand, the latter U-shaped relationship indicates that the ratio of indirectly-employed nonstandard workers initially decreases followed by an increase as the unionization rate reached a certain point. The results from the sample of unionized workplaces reveal a near linear decrease in the relationship between unionization rate and ratio of directly-employed nonstandard workers.

Abstract 5 I. Statement of Problem 7 II. Theoretical Background and Existing Researches 10 1. Theories on Labor Unions and Nonstandard Employment 10 2. Existing Research in Korea 14 III. Empirical Analysis 21 1. Introduction of the Data 21 2. Sample Composition and Descriptive Statistics 22 3. Analysis Model 27 4. Impact of Labor Unions on the Ratio of Nonstandard Workers I (Balanced Panel Sample) 31 5. Impact of Labor Unions on the Ratio of Nonstandard Workers II (Unbalanced Panel Sample) 36 6. Impact of Labor Unions on the Ratio of Nonstandard Workers III (Unionized Workplace Sample in the Unbalanced Panel Sample) 40 IV. Conclusion and Implications 45 References 49