Robust Resource Allocation Decisions in Resource‐Constrained Projects*

The well‐known deterministic resource‐constrained project scheduling problem involves the determination of a predictive schedule (baseline schedule or pre‐schedule) of the project activities that satisfies the finish–start precedence relations and the renewable resource constraints under the objective of minimizing the project duration. This baseline schedule serves as a baseline for the execution of the project. During execution, however, the project can be subject to several types of disruptions that may disturb the baseline schedule. Management must then rely on a reactive scheduling procedure for revising or reoptimizing the baseline schedule. The objective of our research is to develop procedures for allocating resources to the activities of a given baseline schedule in order to maximize its stability in the presence of activity duration variability. We propose three integer programming–based heuristics and one constructive procedure for resource allocation. We derive lower bounds for schedule stability and report on computational results obtained on a set of benchmark problems.     

Modeling and forecasting persistent financial durations

This article introduces the Markov-Switching Multifractal Duration (MSMD) model by adapting the MSM stochastic volatility model of Calvet and Fisher (2004) to the duration setting. Although the MSMD process is exponential β-mixing as we show in the article, it is capable of generating highly persistent autocorrelation. We study, analytically and by simulation, how this feature of durations generated by the MSMD process propagates to counts and realized volatility. We employ a quasi-maximum likelihood estimator of the MSMD parameters based on the Whittle approximation and establish its strong consistency and asymptotic normality for general MSMD specifications. We show that the Whittle estimation is a computationally simple and fast alternative to maximum likelihood. Finally, we compare the performance of the MSMD model with competing short- and long-memory duration models in an out-of-sample forecasting exercise based on price durations of three major foreign exchange futures contracts. The results of the comparison show that the MSMD and the Long Memory Stochastic Duration model perform similarly and are superior to the short-memory Autoregressive Conditional Duration models.     

The development of infants’ sensitivity to native versus non-native rhythm

Speech rhythm is considered one of the first windows into the native language, and the taxonomy of rhythm classes is commonly used to explain early language discrimination. Relying on formal rhythm classification is problematic for two reasons. First, it is not known to which extent infants’ sensitivity to language variation is attributable to rhythm alone, and second, it is not known how infants discriminate languages not classified in any of the putative rhythm classes. Employing a central-fixation preference paradigm with natural stimuli, this study tested whether infants differentially attend to native versus nonnative varieties that differ only in temporal rhythm cues, and both of which are rhythmically unclassified. An analysis of total looking time did not detect any rhythm preferences at any age. First-look duration, arguably more closely reflecting infants’ underlying perceptual sensitivities, indicated age-specific preferences for native versus non-native rhythm: 4-month-olds seemed to prefer the native-, and 6-month-olds the non-native language-variety. These findings suggest that infants indeed acquire native rhythm cues rather early, by the 4th month, supporting the theory that rhythm can bootstrap further language development. Our data on infants’ processing of rhythmically unclassified languages suggest that formal rhythm classification does not determine infants’ ability to discriminate language varieties.     

What Do You Think? The Relationship between Person Reference and Communication About the Mind in Toddlers

The present studies examined the relationship between children's use of grammatical structures indicating self–other differentiation (i.e., personal pronouns, verb conjugation) and their ability to use language to express their own and others' mental states (MSL). In Study 1, 104 parents of two‐ to three‐year‐old children filled out online checklists assessing children's vocabulary, their use of MSL, and first‐ and second‐person pronouns and verb forms. In Study 2, 77 mothers of 1.5‐ to 2.5‐year‐old children filled out the MacArthur–Bates communicative development inventory, and additional checklists for MSL and verb conjugation. Results of both studies showed that children's use of grammatical person reference is strongly related to their level of grammatical abilities. Importantly, pronominal and inflectional references to others were correlated with children's discourse about the mind. Thus, linguistic tools that are used to distinguish self from others are not only indicators of children's grammatical development, but also their level of sociocognitive understanding.     

A self‐motives perspective on feedback‐seeking behavior: Linking organizational behavior and social psychology research

Both the feedback‐seeking literature in management and the self‐motives domain in social psychology have focused on how motives affect the way in which people acquire information for self‐evaluation purposes. Despite apparent conceptual similarities, the implications of research in these domains have not been fully integrated. This paper aims to link research on feedback‐seeking behavior to recent theoretical developments in social psychology. First, the current perspective in management on feedback‐seeking motives is depicted. Second, a well‐established framework of self‐motives in social psychology is introduced. Third, similarities and differences between these two motivational perspectives are discussed and a first step towards integration is proposed. Fourth, it is demonstrated how a self‐motives perspective might guide future research on six key issues. Self‐motives might be useful in identifying new antecedents of feedback‐seeking behavior, resolving inconsistencies in the feedback‐seeking literature, understanding the interplay among feedback‐seeking motives, integrating feedback‐seeking and feedback reactions research, examining attitudinal outcomes of feedback‐seeking motives, and enhancing the feedback–performance relationship.     

High dimensional multivariate mixed models for binary questionnaire data

Summary.  Questionnaires that are used to measure the effect of an intervention often consist of different sets of items, each set possibly measuring another concept. Mixed models with set-specific random effects are a flexible tool to model the different sets of items jointly. However, computational problems typically arise as the number of sets increases. This is especially true when the random-effects distribution cannot be integrated out analytically, as with mixed models for binary data. A pairwise modelling strategy, in which all possible bivariate mixed models are fitted and where inference follows from pseudolikelihood theory, has been proposed as a solution. This approach has been applied to assess the effect of physical activity on psychocognitive functioning, the latter measured by a battery of questionnaires.     

The premium of inflation-indexed life insurances for the Romanian life table

This paper deals with the pricing process of life insurances that provide an insured sum indexed annually according to the current inflation rate. In these terms we propose an appropriate formula for the discount factor. In order to describe the inflation, we consider a stochastic autoregressive model. We deduce analytical expressions for the mean value and the variance of random variable defined as the present value of 1 unit indexed annually according to the inflation rate, payable over t years, when inflation is generated by an autoregressive process of order one. At the same time, we obtain numerical results for the Romanian life table, regarding the mean and the standard deviation for the actuarial present value of a pure endowment life insurance with the sum insured indexed annually with the inflation rate.     

In Memoriam: Martin Taitel,Francis E. McLntyre

A discrete uniform distribution is defined over the integers 1, 2, …, k. Following Tenenbein, who investigated the point estimation of k for a sample drawn without replacement, this paper considers a number of point estimators of k for sampling with replacement and presents conservative confidence sets for k for both methods of sampling.