A missing link: psychological ownership as a mediator between transformational leadership and organizational citizenship behaviour

Interest in psychological ownership (PO) has increased due to its influence on employees’ attitudes and behaviours. This study focuses on PO as a mediator between transformational leadership (TL) and organizational citizenship behaviour (OCB) in the Korean public sector, which does not have employee stock ownership plans (ESOPs). With a total of 214 cases from the Korean public sector, structural equation modelling (SEM) analysis was conducted, and chi-square difference-based model comparison was performed to examine the mediating effect. Results indicated statistically significant relationships between TL and employees’ PO and between employees’ PO and their OCB. A statistically significant full mediating role of PO between TL and OCB in the Korean public sector context was found.     

Landscape of human resource development research in Korea: results from author co-citation network analysis

The present study examined major trends and issues of Human Resource Development (HRD) research in Korean context applying the author co-citation analysis (ACA) to three primary HRD-related journals in South Korea. Following the analyses of author co-citation frequency, correlation matrix, dendrogram, and the multi-dimensional scaling (MDS) map, the results were found as follows: (1) co-citation network identified seven topical clusters (i.e., human competency improvement for young men and e-learning designers, system approach for training effectiveness, competency for executives and HRD-ers, HRD evaluations, HRD solutions, mentoring in career development, leadership, and the role of professionals), (2) competency appeared as a keyword in multiple clusters, (3) unlike HRD in North America or Europe, learning (informal, organizational, self-directed, and lifelong learning) with a variety of HRD solutions comprised the dominant research stream, and (4) research activities for critical issues, such as diversity, development of workforce minority, and international HRD were largely missing.     

Methods for missing covariates in logistic regression

Various methods have been suggested in the literature to handle a missing covariate in the presence of surrogate covariates. These methods belong to one of two paradigms. In the imputation paradigm, Pepe and Fleming (1991) and Reilly and Pepe (1995) suggested filling in missing covariates using the empirical distribution of the covariate obtained from the observed data. We can proceed one step further by imputing the missing covariate using nonparametric maximum likelihood estimates (NPMLE) of the density of the covariate. Recently Murphy and Van der Vaart (1998a) showed that such an approach yields a consistent, asymptotically normal, and semiparametric efficient estimate for the logistic regression coefficient. In the weighting paradigm, Zhao and Lipsitz (1992) suggested an estimating function using completely observed records after weighting inversely by the probability of observation. An extension of this weighting approach designed to achieve semiparametric efficient bound is considered by Robins, Hsieh and Newey (RHN) (1995). The two ends of each paradigm (NPMLE and RHN) attain the efficiency bound and are asymptotically equivalent. However, both require a substantial amount of computation. A question arises whether and when, in practical situations, this extensive computation is worthwhile. In this paper we investigate the performance of single and multiple imputation estimates, weighting estimates, semiparametric efficient estimates, and two new imputation estimates. Simulation studies suggest that the sample size should be substantially large (e.g. n=2000) for NPMLE and RHN to be more efficient than simpler imputation estimates. When the sample size is moderately large (n≤ 1500), simpler imputation estimates have as small a variance as semiparametric efficient estimates.     

Network centrality and performance of social enterprises: Government certified social enterprises in Seoul,South Korea

Social enterprises, which have been dramatically increasing all over the world for several decades, are facing the challenge of how best to develop strategies to improve performance and achieve sustainable growth. In South Korea, the government has supported active networking among social enterprises as a tactic for overcoming insufficient material and human resources. However, it is unclear whether active networking activities among social enterprises are associated with higher performance. In this study, a network survey of certified social enterprises (n = 78) in Seoul, South Korea was conducted. Multivariate regression models examined whether degree centrality, closeness centrality, and betweenness centrality were associated with the economic and social performance of social enterprises after controlling for organizational factors. The results revealed that a social enterprise with higher degree centrality in the network of regular meetings achieved higher social and economic performance.     

Multiscale interpretation of taut string estimation and its connection to Unbalanced Haar wavelets

We compare two state-of-the-art non-linear techniques for nonparametric function estimation via piecewise constant approximation: the taut string and the Unbalanced Haar methods. While it is well-known that the latter is multiscale, it is not obvious that the former can also be interpreted as multiscale. We provide a unified multiscale representation for both methods, which offers an insight into the relationship between them as well as suggesting lessons both methods can learn from each other.