Testing for Heterogeneity with Categorical Data: Permutation Solution vs. Bootstrap Method

In this article the problem of comparing distributional heterogeneities for categorical variables is addressed. Specifically, the one-sided testing problem for heterogeneity comparisons is considered. For such a problem a bootstrap method is proposed and compared with a permutation method already present in literature. The power behavior of the two methods is compared through a Monte Carlo simulation study. The results of two real applications are shown.     

Economy “versus” Environment: The Influence of Economic Ideology and Political Identity on Perceived Threat of Eco‐Catastrophe

Using data from a national survey of American adults, we examine the relationships between economic, political, sociodemographic, and religious characteristics with perception of the potential for eco‐catastrophe. We employ the treadmill of production theory to frame our understanding of views about ecological concerns, arguing that the treadmill discourse associated with economic development is hegemonic and fundamentally shapes public views of eco‐catastrophe. In line with this approach, economic ideology is the strongest predictor of attitudes about eco‐catastrophe, and its influence is conditioned by political identity. There is also significant patterning in these perceptions based on gender, race, education, and religion, but the influence of social characteristics is primarily indirect—mediated by economic ideology and political identity. These results provide useful information for addressing environmental problems in public discourse and bridging policy divides.     

Reliability and Validity of the Pathological Gambling Adaptation of the Yale-Brown Obsessive-Compulsive Scale (PG-YBOCS)

The Yale Brown Obsessive Compulsive Scale adapted for Pathological Gambling (PG-YBOCS) was developed to measure the severity and change in severity of pathological gambling symptoms. The PG-YBOCS is a 10-item clinician-administered questionnaire that measures the severity of PG over a recent time interval (usually within the past one/two week(s)). In order to assess and validate the scale, it was administered to 337 subjects: 188 pathological gamblers and 149 healthy controls. Internal consistency and correlations between individual items and total score were assessed for various permutations of the sample. Other scales were administered to assess convergent, discriminant and content validity. Sensitivity to change was evaluated in treatment studies with fluovoxamine, lithium, and valproate. Each item was frequently endorsed across a range of severity. Good inter-rater reliability and internal consistency were obtained. The PG-YBOCS showed high validity and reliability for total score, item-total correlations, and for each subscale (Thoughts/Urges and Behavior). PG-YBOCS scores correlated with global severity and South Oaks Gambling Screen (SOGS) scores. The scale was also sensitive to change in pathological gambling severity. PG-YBOCS thus appears to be a reliable and valid measure of pathological gambling severity, and can be regarded as an important tool for clinicians and researchers treating pathological gamblers.     

Presenting Results from Model Based Studies to Decision-Makers: Can Sensitivity Analysis be a Defogging Agent?

The motivation of the present work is to provide an auxiliary tool for the decision-maker (DM) faced with predictive model uncertainty. The tool is especially suited for the allocation of R&Dresources. When taking decisions under uncertainties, making use of the output from mathematical or computational models, the DM might be helped if the uncertainty in model predictions be decomposed in a quantitative-rather than qualitativefashion, apportioning uncertainty according to source. This would allow optimal use of resources to reduce the imprecision in the prediction. For complex models, such a decomposition of the uncertainty into constituent elements could be impractical as such, due to the large number of parameters involved. If instead parameters could be grouped into logical subsets, then the analysis could be more useful, also because the decision maker might likely have different perceptions (and degrees of acceptance) for different kinds of uncertainty. For instance, the decomposition in groups could involve one subset of factors for each constituent module of the model; or one set for the weights, and one for the factors in a multicriteria analysis; or phenomenological parameters of the model vs. factors driving the model configuratiodstructure aggregation level, etc.); finally, one might imagine that a partition of the uncertainty could be sought between stochastic (or aleatory) and subjective (or epistemic) uncertainty. The present note shows how to compute rigorous decomposition of the output's variance with grouped parameters, and how this approach may be beneficial for the efficiency and transparency of the analysis.     

Corporate governance effectiveness along the entrepreneurial process of a family firm: the role of private equity

This paper was motivated by the increasing interest in the corporate governance debate on how effective structure and processes may influence entrepreneurial transitions. Along the entrepreneurial process, little research to date has investigated the exit in the context of entrepreneurial family firms. Previous literature has considered the exit mainly as a failure for entrepreneurial families, but when uncertainties arise this choice may enable ownership transitions, thus facilitating survival and long term strategies. Among the exit options, a private equity buyout may balance the family’s wealth protection and the firm’s future growth. However, which family specific characteristics and strategic needs may affect the exit option still remains a neglected topic. Drawing on corporate governance literature and recent research addressing entrepreneurship in family firms, this paper investigates, by a single case study, the bridging role of private equity buyout for going through entrepreneurial transitions. Findings suggest that a private equity buyout is a governance mechanism that may sustain an entrepreneurial transition by realigning family interests and goals. It may also allow the family commitment for improving organizational capabilities required by an entrepreneurial transition.     

A note on multiple testing for composite null hypotheses

Multiple hypothesis testing literature has recently experienced a growing development with particular attention to the control of the false discovery rate (FDR) based on p-values. While these are not the only methods to deal with multiplicity, inference with small samples and large sets of hypotheses depends on the specific choice of the p-value used to control the FDR in the presence of nuisance parameters. In this paper we propose to use the partial posterior predictive p-value [Bayarri, M.J., Berger, J.O., 2000. p-values for composite null models. J. Amer. Statist. Assoc. 95, 1127–1142] that overcomes this difficulty. This choice is motivated by theoretical considerations and examples. Finally, an application to a controlled microarray experiment is presented.     

Global imbalances, exchange rates adjustment and the crisis: Implications from network analysis

The persistence of global imbalances remains a potential source of instability for the international economic system, which ought to be tackled in order to exit from the current crisis in a better position. This paper shows that the complexity of the global network of trade imbalances has increased over time in terms of the number of countries involved and of the heterogeneity of their conditions. These findings imply that orchestrating a global exchange rate adjustment plan, as done in the 1980s to tackle a similar problem, is certainly more difficult than it was 20 years ago. We also show, however, that the uncoordinated movements in bilateral exchange rates occurred since the early 2000s did not go in the direction of reducing bilateral imbalances. Rebalancing the world economy, thus, seems to require a rich set of coordinated policy actions and economic changes, involving adjustments in both exchange rates and real variables, which are heterogeneous at the country level. We argue that, provided some conditions are satisfied, the variegated effects of the ongoing financial crisis, and the policy responses this has induced, may help the global and bilateral rebalancing process.