Network Positions and the Probability of Being Acquired: An Empirical Analysis in the Biopharmaceutical Industry

This paper examines the relationship between the firm's direct ties, its inter‐firm network prominence and its likelihood of being acquired. The authors argue that firm's direct ties and prominence enhance the firm's visibility and signal its quality – and thus foster the firm's likelihood of being acquired. However, higher levels of direct ties and prominence, by providing access to resources and the firm's status, respectively, increase the firm's ability to remain independent and thus reduce its likelihood of being acquired. Thus, the authors posit the overall relation as an inverted U‐shaped. Furthermore, they show that, for firms that undergo an initial public offering, the aforementioned relation becomes much weaker. The hypotheses are empirically tested in the biopharmaceutical industry and important theoretical and managerial implications are discussed.     

And yet it moves! (Climate) migration as a symptom in the Anthropocene

ABSTRACT

While the climate-migration nexus raises crucial questions of mobility and climate justice, it is commonly understood through simplistic narratives that reify a complex set of relations. The spectre of environmentally-induced exodus is recurrent in media, policy and activist circles, in spite of numerous studies that reveal the empirical flaws and noxious normative implications of such narratives. This article explores this insistence and the desire(s) for there to be a reified relation between climate and migration such insistence reveals. The article proceeds in three movements. First, it situates discourses on climate migration in relation to the crisis of humanism the Anthropocene signifies. Second, it operates a symptomatic reading of climate migration discourses, drawing on two understandings of symptom elaborated by Lacan – as ‘return of the repressed’ and as ‘Sinthome’. Read as a symptom, the figure of the climate migrant/refugee appears as the return of fundamental contradictions that carve contemporary regimes of socioecological (re)production. Through the concept of ‘Sinthome’, discourses on climate migration can be read as (illusory) attempts to shore up for the waning consistence of modern forms of ‘being human’. Finally, the article proposes a symptomatic reading of the Anthropocene itself, and elaborates on what the dissolution of this symptom/ Sinthome would entail.     

Minimax,information and ultrapessimism

Discussing the foundations of the minimax principle, Savage (1954) argued that it is utterly untenable for statistics because it is ultrapessimistic when applied to negative income, but claimed that such objection is not relevant when the principle is applied to regret. In this paper I rebut the latter claim. I first present an example where ultrapessimism, as Savage understood it, applies to minimax regret but not to minimax negative income. Then, for a sequential decision problems with two terminal acts and a finite number of states of nature, I give necessary and sufficient conditions for a decision rule to be ultrapessimistic, and show that for every payoff table with at least three states, be it in regret form or not, there exist an experiment such that the minimax rule is ultrapessimistic. I conclude with some more general remarks on information and the value of experimentation for a minimax agent.     

Factor Structure and Convergent Validity of the Long and Abbreviated Versions of the Multidimensional Students’ Life Satisfaction Scale in an Italian Sample

We examined the psychometric characteristics of the long and abbreviated versions of the Multidimensional Students’ Life Satisfaction Scale (MSLSS) in the Italian contexts. In study 1 we assessed the factorial validity and reliability of the long and abbreviated versions of the MSLSS among Italian adolescents, while in study 2 we assessed the convergent validity of the abbreviated Italian version of the MSLSS by examining the associations between life satisfaction and well-established measures of adjustment. Furthermore, we explored the effect of adolescent gender and age on life satisfaction. Participants in the study 1 were 996 adolescents (48 % males) from 14 to 18 years of age (M = 16.06; SD = 1.51). Participants in study 2 were 380 adolescents (52 % males) from 14 to 19 years of age (M = 15.76; SD = 1.65). Confirmatory factor analyses confirmed the hypothesized five-factor solution of the MSLSS, with a better goodness of fit for the abbreviated version of MSLSS. Moreover, indices of internal consistency revealed acceptable reliability coefficients across the five domains. Convergent validity was confirmed by the expected associations between the domains of the MSLSS and indexes of adjustment. Finally, results evidenced age differences, with oldest adolescents showing the highest levels of satisfaction on most of the domains.     

Estimating percentile-specific treatment effects in counterfactual models: a case-study of micronutrient supplementation, birth weight and infant mortality

Summary.  Clinical trials of micronutrient supplementation are aimed at reducing the risk of infant mortality by increasing birth weight. Because infant mortality is greatest among the low birth weight (LBW) infants (2500 g or under), an effective intervention increases the birth weight among the smallest babies. The paper defines population and counterfactual parameters for estimating the treatment effects on birth weight and on survival as functions of the percentiles of the birth weight distribution. We use a Bayesian approach with data augmentation to approximate the posterior distributions of the parameters, taking into account uncertainty that is associated with the imputation of the counterfactuals. This approach is particularly suitable for exploring the sensitivity of the results to unverifiable modelling assumptions and other prior beliefs. We estimate that the average causal effect of the treatment on birth weight is 72 g (95% posterior regions 33–110 g) and that this causal effect is largest among the LBW infants. Posterior inferences about average causal effects of the treatment on birth weight are robust to modelling assumptions. However, inferences about causal effects for babies at the tails of the birth weight distribution can be highly sensitive to the unverifiable assumption about the correl-ation between the observed and the counterfactuals birth weights. Among the LBW infants who have a large causal effect of the treatment on birth weight, we estimate that a baby receiving the treatment has 5% less chance of death than if the same baby had received the control. Among the LBW infants, we found weak evidence supporting an additional beneficial effect of the treatment on mortality independent of birth weight.     

The variable parameters T ^{2} chart with run rules

The Hotelling’s \(\textit{T}^{2 }\) control chart with variable parameters (VP \(T^{2})\) has been shown to have better statistical performance than other adaptive control schemes in detecting small to moderate process mean shifts. In this paper, we investigate the statistical performance of the VP \(T^{2}\) control chart coupled with run rules. We consider two well-known run rules schemes. Statistical performance is evaluated by using a Markov chain modeling the random shock mechanism of the monitored process. The in-control time interval of the process is assumed to follow an exponential distribution. A genetic algorithm has been designed to select the optimal chart design parameters. We provide an extensive numerical analysis indicating that the VP \(T^{2}\) control chart with run rules outperforms other charts for small sizes of the mean shift expressed through the Mahalanobis distance.     

Asymptotics for Panel Models with Common Shocks

This article develops a novel asymptotic theory for panel models with common shocks. We assume that contemporaneous correlation can be generated by both the presence of common regressors among units and weak spatial dependence among the error terms. Several characteristics of the panel are considered: cross-sectional and time-series dimensions can either be fixed or large; factors can either be observable or unobservable; the factor model can describe either a cointegration relationship or a spurious regression, and we also consider the stationary case. We derive the rate of convergence and the limit distributions for the ordinary least square (OLS) estimates of the model parameters under all the aforementioned cases.     

Well-Being and Affective Commitment among Ambulance Volunteers: A Mediational Model of Job Burnout

ABSTRACT

Burnout represents a relevant risk for ambulance volunteers. According to the Job Demands-Resources model, role conflict and social support can be considered as antecedents of burnout which, in turn, may lower affective commitment. This study aims to investigate the relationship between social support, role conflict, and affective commitment, as mediated by job burnout. Survey data were collected from 352 Italian volunteers and analyzed using structural equation modeling methods. Social support was confirmed as a protective factor, and role conflict as an antecedent of burnout which, in turn, decreases affective commitment. The relationship between role conflict and affective commitment is mediated by burnout which, on the contrary, does not mediate the effect of social support on affective commitment. Social support may protect against burnout. Because of its positive effects on a personal and an organizational level, affective commitment may be increased raising levels of supervisor support and reshaping role expectations. It could be useful to carry out future longitudinal studies, in order to confirm the antecedents and effects of job burnout; furthermore, this research should be extended to other ambulance organizations, in order to generalize the results; finally, multi-group analyses would allow to bring out possible differences between paid-staff and volunteers.     

Comparing and generating Latin Hypercube designs in Kriging models

In Computer Experiments (CE), a careful selection of the design points is essential for predicting the system response at untried points, based on the values observed at tried points. In physical experiments, the protocol is based on Design of Experiments, a methodology whose basic principles are questioned in CE. When the responses of a CE are modeled as jointly Gaussian random variables with their covariance depending on the distance between points, the use of the so called space-filling designs (random designs, stratified designs and Latin Hypercube designs) is a common choice, because it is expected that the nearer the untried point is to the design points, the better is the prediction. In this paper we focus on the class of Latin Hypercube (LH) designs. The behavior of various LH designs is examined according to the Gaussian assumption with exponential correlation, in order to minimize the total prediction error at the points of a regular lattice. In such a special case, the problem is reduced to an algebraic statistical model, which is solved using both symbolic algebraic software and statistical software. We provide closed-form computation of the variance of the Gaussian linear predictor as a function of the design, in order to make a comparison between LH designs. In principle, the method applies to any number of factors and any number of levels, and also to classes of designs other than LHs. In our current implementation, the applicability is limited by the high computational complexity of the algorithms involved.     

The flower intersection problem for Kirkman triple systems

The flower at a point x in a Steiner triple system is the set of all triples containing x. Denote by I_R^*[r] the set of all integers k such that there exists a pair of KTS(2r+1) having k+r triples in common, r of them being the triples of a common flower. In this article we determine the set I_R^*[r] for any positive integer r≡1 (mod 3) (only nine cases are left undecided for r=7,13,16,19), and establish that I_R^*[r]=J[r] for r≡1 (mod 3) and r22 where J[r]={0,1,…,2r(r−1)/3−6,2r(r−1)/3−4,2r(r−1)/3}.