Identification-robust moment-based tests for Markov switching in autoregressive models

ABSTRACT

This paper develops tests of the null hypothesis of linearity in the context of autoregressive models with Markov-switching means and variances. These tests are robust to the identification failures that plague conventional likelihood-based inference methods. The approach exploits the moments of normal mixtures implied by the regime-switching process and uses Monte Carlo test techniques to deal with the presence of an autoregressive component in the model specification. The proposed tests have very respectable power in comparison with the optimal tests for Markov-switching parameters of Carrasco et al. (2014 Carrasco, M., Hu, L., Ploberger, W. (2014). Optimal test for Markov switching parameters. Econometrica 82(2):765–784.[Crossref], [Web of Science ®] , [Google Scholar]), and they are also quite attractive owing to their computational simplicity. The new tests are illustrated with an empirical application to an autoregressive model of USA output growth.     

Finite-sample Resampling-based Combined Hypothesis Tests,with Applications to Serial Correlation and Predictability

This article suggests Monte Carlo multiple test procedures which are provably valid in finite samples. These include combination methods originally proposed for independent statistics and further improvements which formalize statistical practice. We also adopt the Monte Carlo test method to noncontinuous combined statistics. The methods suggested are applied to test serial dependence and predictability. In particular, we introduce and analyze new procedures that account for endogenous lag selection. A simulation study illustrates the properties of the proposed methods. Results show that concrete and nonspurious power gains (over standard combination methods) can be achieved through the combined Monte Carlo test approach, and confirm arguments in favor of variance-ratio type criteria.     

Changes in Employment Uncertainty and the Fertility Intention–Realization Link: An Analysis Based on the Swiss Household Panel

How do changes in employment uncertainty matter for fertility? Empirical studies on the impact of employment uncertainty on reproductive decision-making offer a variety of conclusions, ranging from gender and socio-economic differences in the effect of employment uncertainty on fertility intentions and behaviour, to the effect of employment on changes in fertility intentions. This article analyses the association between a change in subjective employment uncertainty and fertility intentions and behaviour by distinguishing male and female partners’ employment uncertainty, and examines the variation in these associations by education. Using a sample of men and women living in a couple from the Swiss Household Panel (SHP 2002–2011), we examine through multinomial analysis how changes in employment uncertainty and selected socio-demographic factors are related to individual childbearing decisions. Our results show strong gendered effects of changes in employment uncertainty on the revision of reproductive decisions among the highly educated population.     

Resilience and risk competence in schools: theory/knowledge and international application in project rebound

Despite a 50-year interdisciplinary and longitudinal research legacy--showing that nearly 80% of young people considered most "at risk" thrive by midlife-only recently have practitioners/researchers engaged in the explicit, prospective facilitation of "resilience" in educational settings. Here, theory/knowledge distinguishing and extending risk and resilience from its risk-based social history to resilience's normative occurrence leads to the first known international and prospective application of resilience in school-based drug education, Project REBOUND [resilience-bound]. It will be implemented as a controlled pilot study, first in Germany, then expand to the United States, as well as other parts of Europe. With evaluation occurring throughout, the goal is to enhance the quality of drug decisions among young people, as well as support their overall competence-based learning and development throughout school. With limitations and underlying psychological mechanisms discussed, it is concluded Project REBOUND offers promising potential for supporting positive drug decisions as well as youth learning and development.     

Income taxation of couples and the tax unit choice

We study the optimal income taxation of couples. We determine the resulting intra-family labor supply allocation and its implication for the choice of the tax unit (individual versus joint taxation). We provide a general condition for full joint taxation to arise. We also study how the spouses’ respective labor supply decisions are distorted when the condition does not hold. In particular, we show that, depending on the pattern of mating, the celebrated result according to which the spouse with the more elastic labor supply faces the lower marginal tax rates may or may not hold in our setting.     

Instrument endogeneity and identification-robust tests: Some analytical results

When some explanatory variables in a regression are correlated with the disturbance term, instrumental variable methods are typically employed to make reliable inferences. Furthermore, to avoid difficulties associated with weak instruments, identification-robust methods are often proposed. However, it is hard to assess whether an instrumental variable is valid in practice because instrument validity is based on the questionable assumption that some of them are exogenous. In this paper, we focus on structural models and analyze the effects of instrument endogeneity on two identification-robust procedures, the Anderson–Rubin (1949, AR) and the Kleibergen (2002, K) tests, with or without weak instruments. Two main setups are considered: (1) the level of “instrument” endogeneity is fixed (does not depend on the sample size) and (2) the instruments are locally exogenous, i.e. the parameter which controls instrument endogeneity approaches zero as the sample size increases. In the first setup, we show that both test procedures are in general consistent against the presence of invalid instruments (hence asymptotically invalid for the hypothesis of interest), whether the instruments are “strong” or “weak”. We also describe cases where test consistency may not hold, but the asymptotic distribution is modified in a way that would lead to size distortions in large samples. These include, in particular, cases where the 2SLS estimator remains consistent, but the AR and K tests are asymptotically invalid. In the second setup, we find (non-degenerate) asymptotic non-central chi-square distributions in all cases, and describe cases where the non-centrality parameter is zero and the asymptotic distribution remains the same as in the case of valid instruments (despite the presence of invalid instruments). Overall, our results underscore the importance of checking for the presence of possibly invalid instruments when applying “identification-robust” tests.     

Online epistemic communities: theoretical and methodological directions for understanding knowledge co-elaboration in new digital spaces

This paper presents, illustrates and discusses a generic framework for studying knowledge co-elaboration in online epistemic communities ("OECs"). Our approach is characterised by: considering knowledge co-elaboration as a design activity; distinguishing discussion and production spaces in OECs; characterising participation via the notion of role; fine-grained analyses of meaning, content and communicative functions in interactions. On this basis, three key issues for ergonomics research on OECs are discussed and illustrated by results from our previous studies on OSS and Wikipedia. One issue concerns the interrelation between design (task) and regulation. Whereas design task-oriented activity is distributed among participants, we illustrate that OCEs function with specialised emerging roles of group regulation. However, the task-oriented activity also functions at an interpersonal level, as an interplay of knowledge-based discussion with negotiation of competencies. Another issue concerns the foci of activity on the (designed) knowledge object. Based on a generic task model, we illustrate asymmetry and distinctiveness in tasks' foci of participants. The last issue concerns how design-use mediation is ensured by specific forms of mediation roles in OECs. Finally we discuss the degree of generality of our framework and draw some perspectives for extending our framework to other OECs.     

In hindsight and now again: black male teachers’ recollections on the suffering of black male youth in US public schools

This article draws from data in a larger qualitative study on the lives of black male teachers in US public urban schools. I examine their schooling experiences as black male youth. By coupling theories of social suffering with life history methodology, this research analyzes how three black male teachers experienced frustration, marginalization, and misery as students. For these participants, academic tracking was a site of social suffering. This suffering persisted into their adult lives as classroom teachers, as they witnessed and attempted to mitigate the struggles of their own black male students. The findings in this study have implications for further research on black male teachers as well as their recruitment and retention in US public schools.     

The impact of human resource management on organisational performance: Theory and research

This article by Jean-Marie Hiltrop, considers some of the models which have studied the link between HRM and organisational performance. As yet, there is little real evidence, but it is growing and indicates that corporate HRM policies and practices - including ‘best’ practices - are associated with high (financial) performance, and can encourage employee behaviour and attitudes towards strengthening the competitive strategy of an organisation. But such ‘best’ practices can vary widely and even contradict each other. Questions are raised in the article about these ‘best’ practices.The first part of the article looks at the relevant theoretical models, and the second part reviews the findings of recent empirical studies which have evaluated the effects of distinctive HR practices on organisational outcomes.