2.1. Corporate Social Responsibility
CSR is defined as the voluntary organizational actions and policies that seek social well-being, far beyond just the interests of firms and legislative requirements [
19,
20]. Since CSR activities are not mandatory in operating a company, many questions have been raised about whether costly CSR activities are conducive to business performance. Thus, there are two opposing opinions about the association between CSR and financial performance [
6]. As a negative opinion, it is argued that management should be careful in making decisions about CSR activities because of the ongoing costs of firms’ CSR activities. On the other hand, as a positive opinion, it is argued that management should encourage firms’ CSR activities because they can boost financial performance by increasing corporate vigor.
Most US or European studies have supported the positive opinion by documenting the results of a positive association between firms’ CSR activities and financial performance [
6,
7,
8,
9]. Cochran and Wood (1984) improved their research model by adding control variables of asset turnover and asset age, and they found that CSR is positively correlated with financial performance [
6]. McGuire et al. (1988) suggested that CSR can not only lower firms’ risks, but it can also increase accounting-based financial performance [
7]. Tsoutsoura (2004) investigated S&P 500 firms during the 1996–2000 period and suggested a result consistent with those of prior studies, reporting that CSR positively contributes to improving financial performance [
8]. Orlitzky et al. (2003), conducting meta-analyses, reported that there is a positive association between corporate social performance and financial performance [
9]. This means that an entity’s CSR activities can have a positive impact on its performance. For recent studies, using various CSR engagement, market-based, and accounting-based performance measures, Blasi et al. (2018) suggested that CSR engagement is strongly positively associated with total stock returns, but accounting performance, shows difference depending on industry sectors [
21]. Put differently, US tech firms with higher CSR spending are more likely to show greater financial performance, measured by ROA and ROE [
22].
The result of a company’s CSR activities having a positive impact on its financial performance has been reported in Korean studies as well [
23,
24,
25]. Cho et al. [
23] showed that, partly, CSR performance is positively associated with firm performance in terms of profitability, the growth rate of total assets, corporate soundness, and social contribution. Lee and Lee [
24] found that the association between CSR performance and firm performance such as sustainable growth and valuation is non-linear, rather than a linear relationship. Lau et al. [
25] examined the moderating effect of corporate governance between CSR performance and operational performance in Korea. Specifically, they investigated 209 Korean manufacturing companies and indicated that CSR is significantly associated with operational performance; this association is positively moderated by law enforcement and competition intensity. Chung et al. [
26] supported the positive view between CSR and firm performance while assuming that firms engage in CSR activities not because of corporate image but because of strategic purposes. In addition, previous studies in the literature examined the effectiveness of CSR on a company’s activities from many aspects, not only for performance, but for the company and society. Beaudoin (2008) and Chih et al. (2008) reported that CSR companies provide more ethical accounting information than do non-CSR companies and disclose news on time, even when they have bad news [
27,
28]. CSR activities are also positively associated with company charity [
28]. Through this kind of action, a company can build a positive reputation among stakeholders and gives a signal to shareholders that the company engages in activities toward social welfare.
Recent CSR-related studies have been conducted on the association between CSR perception and employee behaviors [
29,
30,
31,
32,
33,
34]. Akremi (2018) and Jones (2010) argued that CSR enables employees to be positively committed to the organization [
30,
31]. Jones et al. (2014) reported that CSR can attract job seekers, in that job seekers tend to be hired by socially responsible firms [
32]. Onkila (2015) and Zhou et al. (2018) reported that CSR activities can positively alter employee perceptions of a company and lead them to high commitment to firms [
33,
34]. Furthermore, some studies conducted since 2020 reflect the peculiarities of the pandemic era. Many of these studies have dealt with exploring the impact of CSR at a time when the stock market has crashed and many companies have suffered financially as a side effect of the pandemic. Qiu et al. (2021) investigated the effect of CSR activities in China on the stock price return of individual companies during the COVID-19 pandemic with data from China and showed that CSR activities have an effect on the stock price return and positive impression on shareholders [
35]. Albuquerque et al. (2020) analyzed the first quarter of the US stock market’s 2020 data and found that higher CSR firms gained significantly positive gains in earnings, earnings volatility, and operating margin in the crisis period [
36]. Overall, prior studies show that, as a business strategy, CSR activities play a positive role in corporate sustainability in terms of financial performance and the employment environment.
2.2. Regular Employment and Non-Regular Employment
This study defines sustainable employability as the ability of companies to provide their employees with a sustainable working environment that allows them to engage in long-term, healthy, and happy work. Each country has its own employment policies according to its political and social characteristics [
37,
38]. The terminology that distinguishes employment types vary with countries. For instance, the US widely uses the terms of permanent and non-permanent employees; Canada and New Zealand use standard employees and precarious employees [
37]. Korea uses the terms regular employees and non-regular employees [
38]. Hereafter, in this study, we decided to use the term regular and non-regular employees.
In the case of Korean companies, employees are classified as regular or non-regular depending on whether the retirement age is guaranteed. In general, regular employees in Korea can work stably until retirement age regardless of their work performance. On the other hand, for non-regular employees, it is very difficult to renew a contract when it expires, regardless of work performance. In addition, non-regular employees have few chances to get a promotion or switch to regular positions [
39]. This indicates that in order to work in Korea in a stable, healthy, and happy manner, one should be hired as a regular employee rather than a non-regular employee. We consider that this working environment, where such differences between regular and non-regular employees are clear, is a good research setting to study sustainable employability.
The existing literature on human resources approaches various theoretical backgrounds such as internal labor market theory, resource-based theory, and real option theory, and it explains the provided reasons why firms employ non-regular employees [
40]. The literature suggests that firms can increase labor flexibility to optimize their operation by hiring many non-regular employees. However, several studies have raised questions regarding the effectiveness of non-regular employees, meaning that the employment of non-regular employees may worsen firm performance in the long term given that the employment of non-regular employees and labor productivity have an inverse relation [
41,
42,
43,
44,
45]. Because of disadvantages in terms of wages, vacation time, and job security between regular and non-regular employees, non-regular employees have low loyalty and satisfaction in their company, leading to a downgrade in quality control and firm performance [
46]. In other words, firms basically hire non-regular employees in order to relax the high labor costs of hiring mostly regular employees; however, in doing so, they may also sacrifice employee loyalty, the degree of skill, and control against savings on labor costs and employment flexibility, meaning that such sacrifice outweighs the cost savings, with decreased labor productivity and increased negative effects on non-regular employees. Overall, recent studies have emphasized a higher proportion of regular employees compared to non-regular employees to enhance sustainable firm performance in the long term. That is, more non-regular employees may decrease firm performance.
2.3. Hypothesis Development
Companies can easily hire or fire non-regular employees depending on the economic conditions, allowing them to manage their profits by altering employee-related expenses. As a result, there is an incentive for companies to increase labor flexibility by hiring non-regular employees rather than regular employees.
However, non-regular employees have lower commitment and loyalty to companies than regular employees [
46]. They may have anxiety regarding job insecurity, and they will not put in extra effort for their firms. Ultimately, this job insecurity for non-regular employees may cause an overall unfavorable outcome for their firms’ financial performance [
47,
48,
49,
50]. Prior studies reported that a firm’s CSR activities can not only increase employee satisfaction but also reduce employee turnover [
51,
52,
53]. Therefore, we predict that companies performing CSR activities are making more efforts to increase sustainable employability. Hence, we propose the following Hypothesis 1.
Hypothesis 1 (H1). There is a significantly positive association between firms’ CSR activity status and the level of sustainable employability.
Additionally, we believe that companies with high CSR activity will provide better job security and a better working environment compared to those with low CSR activity. To investigate the link between CSR index scores and sustainable employability, we assumed that within a group of companies performing CSR activities, a company with higher CSR activities will have more sustainable employability than a company with lower CSR activities. Therefore, we propose the following Hypothesis 2.
Hypothesis 2 (H2). There is a significantly positive association between CSR index score and the level of sustainable employability.