A Study on the Relationship between Multiple Job Holding (MJH) and the Types of Precarious Labor In South Korea

Background and Purpose

The purpose of this study is to empirically analyze the types of precarious labor experienced by individual workers in South Korea, who hold two or more jobs at a given time (called multiple job holders). Here, "precarious labor" refers to instability in employment, income, and social insurance (Lee et al., 2019).

Recently in Korea, with the emergence of the COVID-19 pandemic and the rise of Platform labor and freelancers, the number of people holding one or more jobs has been increasing. In particular, while participation in multiple jobs was previously higher among those with lower educational attainment, there is now a growing trend of workers with a university degree or higher. Also, among young people, there is a rising proportion of those working in the retail, food and accommodation sectors, which are well known for precarious jobs in Korea. This suggests the need to examine the causes of the increase in multi-job workers and the characteristics of their unstable labor.

Therefore, this study first reviews the concept of multi-job holding and examines its relationship with the precarious labor condition. It then uses data from the 25th wave of the Korean Labor and Income Panel Study (KLIPS) to empirically analyze what types of precarious labor market conditions multi-job holders experience, employing Propensity Score Matching method and post-matching logistic regression analysis.

Methods

Data and Sample: this study utilized a merged data of “individual” and “work history” datasets from 25^th wave (year 2022) of the Korean Labor and Income Panel Study(KLIPS). The sample of this analysis includes 2,847 individuals.

Measures: the dependent variable of this study is "precarious labor", which measures employment instability, income instability and social insurance instability. The independent variable is "participation in simultaneous employment." Control variables include socio-demographic characteristics(gender, age, education level) and job characteristics(company size, occupation, industry type, trade union status).

analytic strategy: this study used propensity score matching(PSM) and post-matching regression analysis to examine how participation in multiple jobs affects experiences of precarious labor. PSM is used to reduce endogeneity when comparing two groups.

Results

The results show that multi-job holders were more likely to fall into "social insurance instability" in their primary job compared to non-multiple job holders. There was no significant relationship found for employment and income instability. This suggests that the instability of employment and income in the primary job is offset by the other non-primary jobs. However, having more than one job leads to conflicts regarding social insurance because social insurance tends to cover only the primary job.

Conclusions and Implications

This study does not reveal that multi-job holders do not experience employment or income instability at all. Rather, it aimed to demonstrate that multi-job holders are highly likely to face social insurance instability compared to other types of workers. In particular, the study highlights the instability in “health insurance,” which addresses that multi-job holders face the disadvantages in terms of health, despite the fact that they require greater attention to their health due to holding too much jobs.