Moment and IV Selection Approaches: A Comparative Simulation Study

We compare three moment selection approaches, followed by post-selection estimation strategies. The first is adaptive least absolute shrinkage and selection operator (ALASSO) of Zou (2006 Zou, H. (2006). The adaptive lasso and its oracle properties. Journal of the American Statistical Association 101:1418–1429.[Taylor &; Francis Online], [Web of Science ®] , [Google Scholar]), recently extended by Liao (2013 Liao, Z. (2013). Adaptive GMM shrinkage estimation with consistent moment selection. Econometric Theory FirstView:1–48. [Google Scholar]) to possibly invalid moments in GMM. In this method, we select the valid instruments with ALASSO. The second method is based on the J test, as in Andrews and Lu (2001 Andrews, D. W. K., Lu, B. (2001). Consistent model and moment selection procedures for GMM estimation with application to dynamic panel data models. Journal of Econometrics 101(1):123–164.[Crossref], [Web of Science ®] , [Google Scholar]). The third one is using a Continuous Updating Objective (CUE) function. This last approach is based on Hong et al. (2003 Hong, H., Preston, B., Shum, M. (2003). Generalized empirical likelihood based model selection criteria for moment condition models. Econometric Theory 19(06):923–943. [Google Scholar]), who propose a penalized generalized empirical likelihood-based function to pick up valid moments. They use empirical likelihood, and exponential tilting in their simulations. However, the J-test-based approach of Andrews and Lu (2001 Andrews, D. W. K., Lu, B. (2001). Consistent model and moment selection procedures for GMM estimation with application to dynamic panel data models. Journal of Econometrics 101(1):123–164.[Crossref], [Web of Science ®] , [Google Scholar]) provides generally better moment selection results than the empirical likelihood and exponential tilting as can be seen in Hong et al. (2003 Hong, H., Preston, B., Shum, M. (2003). Generalized empirical likelihood based model selection criteria for moment condition models. Econometric Theory 19(06):923–943. [Google Scholar]). In this article, we examine penalized CUE as a third way of selecting valid moments.

Following a determination of valid moments, we run unpenalized generalized method of moments (GMM) and CUE and model averaging technique of Okui (2011 Okui, R. (2011). Instrumental variable estimation in the presence of many moment conditions. Journal of Econometrics 165(1):70–86.[Crossref], [Web of Science ®] , [Google Scholar]) to see which one has better postselection estimator performance for structural parameters. The simulations are aimed at the following questions: Which moment selection criterion can better select the valid ones and eliminate the invalid ones? Given the chosen instruments in the first stage, which strategy delivers the best finite sample performance?

We find that the ALASSO in the model selection stage, coupled with either unpenalized GMM or moment averaging of Okui delivers generally the smallest root mean square error (RMSE) for the second stage coefficient estimators.     

Selection of Logistic Service Providers for the transportation of refrigerated goods

The aim of this article is to propose a decision model based on Analytic Hierarchy Process (AHP) for the evaluation and selection of Logistics Service Providers (LSPs) for a refrigerated products company. The results indicated that quality, responsiveness and reliability are the most important criteria for selecting an LSP for the transportation of perishable refrigerated goods, considering contractor’s profile, which is based on protection of its brand and reputation in the market. In addition, sensitivity analysis is performed to verify priority ranking stability. Therefore, this research illustrates how AHP model could be implemented to help the decision-making process for selecting third-party services in logistics for perishable refrigerated goods effectively.     

Four-stage process model of the core factors of burnout: The role of work stressors and work-related resources

The impact of work stressors and work-related resources on emotional exhaustion and depersonalization, as the two core factors of burnout, is investigated. According to the German Action Regulation Theory work stressors are conceptualized as regulation problems that lead to work stress in terms of additional effort (e.g. working longer hours), increased intensity of effort (e.g. working at a faster pace), and risky action (e.g. by neglecting safety rules). Consequently, an extended process model consisting of objective work stressors, work stress, emotional exhaustion and depersonalization is proposed. Nurses from three general hospitals (N=482) provided data for evaluating this model. Complete mediation of work stress and emotional exhaustion were analysed by hierarchical regression analysis. The overall model was tested by structural equation analysis in two steps; in the first step the basic model was analysed while in the second step the model was extended by autonomy as a work-related resource. The process model could be confirmed with respect to: (1) the mediating function of work stress and emotional exhaustion, and with regard to (2) the direct impact of autonomy as a work-related resource on work stressors but not on emotional exhaustion and depersonalization. Methodological considerations and implications for work design and burnout prevention are discussed.     

Preparing for business model change: the “pre-stage” finding

The purpose of this paper is to investigate managers’ initiatives in the context of an emergent technology and their effect on the business models of firms. Building on four case studies of organizations interested in using an emergent technology for commercial purposes, this study applies a process-based framework of business model change. The main finding is that managers’ initiatives occur in the context of a “pre-stage” of potential business model change, which includes processes of experimenting and learning. The pre-stage finding gives a better understanding of when change initiatives affect a business model and when they do not, allowing managers to adopt a more proactive behaviour and guide their organizations towards effective business model change. The main contribution of this paper is to suggest the inclusion of the pre-stage idea in research and practice, since it is an intermediary step in the process of business model change that has been overlooked.     

Welfare, labor supply and heterogeneous preferences: evidence for Europe and the US

Following the report of the Stiglitz Commission, measuring and comparing well-being across countries has gained renewed interest. Yet, analyses that go beyond income and incorporate non-market dimensions of welfare most often rely on the assumption of identical preferences to avoid the difficulties related to interpersonal comparisons. In this paper, we suggest an international comparison based on individual welfare rankings that fully retain preference heterogeneity. Focusing on the consumption-leisure trade-off, we estimate discrete choice labor supply models using harmonized microdata for 11 European countries and the US. We retrieve preference heterogeneity within and across countries and analyze several welfare criteria which take into account that differences in income are partly due to differences in tastes. The resulting welfare rankings clearly depend on the normative treatment of preference heterogeneity with alternative metrics. We show that these differences can indeed be explained by estimated preference heterogeneity across countries—rather than demographic composition.     

Books received as of April 30, 1985

This research focuses on insiders’ views of marital sex and their dyadic patterning. The analyses were conducted based on seventy‐two (72) couples’ assessments of their recent sexual interactions. Non‐genital and genital activities were assessed as a function of the respondents’ and the actors’ gender, and as a function of constructs that were specific to the marital partners as individuals and as a marital dyad. Consistent differences were found between husbands’ and wives’ perceptions of discrepancies within their couple. Regardless of respondents’ gender, couples reported that wives were genitally less active than husbands and that this was in accordance with the wives’ preferences. The results are discussed with respect to the advantages of using a dyadic methodology for measuring dimensions of sex which involve interpersonal behaviors.     

Towards a Sociocultural Perspective on Identity Formation in Education

This article discusses a sociocultural approach to processes of identity that has implications for how we understand learning and identity formation in education. Focusing on the socially constructed and culturally figured nature of language, tools, and interactions in learning contexts, this approach assists in the appreciation of how students navigate through and develop an understanding of themselves in different educational contexts. To this end, reference is made to Wortham's work on interactional positioning in narratives and the work of Holland and colleagues on figured worlds. Wortham provides the tools for a systematic analysis of how individuals construct their identities by positioning themselves in discursive interaction. Holland and colleagues alert us to the cultural shaping of such positioning in cultural worlds and the artifacts mediating identity formation. To explore the potential of combining these lenses, a case study is described involving a series of interviews with medical students about their self-perceptions in two contexts of clinical training. The case study highlights how different worlds and identities are formed in these educational contexts.     

A gender story of institutional disengagement of young adults in Latin America

Latin America is home to many young adults who are neither engaged in formal education nor work, controversially dubbed as “nini” (“ni” trabajan “ni” estudian, denoting neither working nor studying). At the same time, early union formation and parenthood are pervasive in the region. Theories pertaining to the linkage between parenthood and female labor force participation are heavily based on evidence found in the Global North, with limited research on the topic in settings with less stable family structures, such as Latin American countries. This study tests the role household structure and family formation play on institutional disengagement of young adults in 12 Latin American countries. We explore the gender dynamic of human capital stagnation by focusing on early parenthood and conjugal partnership for women and men aged 20–25. We use censuses from the Integrated Public-Use Microdata Series and country-specific linear regression models. Our results reveal that the intersection of class and gender is a major determinant of institutional disengagement in the region. Women from lower social origins who leave parental home to enter conjugal union and parenthood at younger ages are particularly at risk. This study highlights the urgency of contextualizing the interplay between work and family within the framework of regional family norms, prompting further dialogues concerning the social implications of perceived inactivity.