On the interpretation of cointegration in the linear–quadratic inventory model

The traditional formulation of the linear–quadratic inventory model with unit roots predicts cointegration between inventories and sales. That formulation implies that marginal production costs and the marginal benefits of inventories are both tending to ∞, and the cointegrating coefficient reflects the optimal trade-off between these competing factors. This paper suggests a reformulation of the problem in which marginal production costs and marginal inventory benefits are both stationary and in which the cointegrating coefficient is the same as the value that characterizes the target inventory level in the cost function.     

Labour inclusion of people with disabilities in Spain: the effect of policies and human resource management systems

Abstract

This research answered the question of which elements, linked to HR management, facilitate the labour inclusion of people with disabilities. We analysed the existence of policies in different organizations, and the interaction between these policies and the adaptation of the human resource management systems in order to archive effective labour inclusion. Spanish Human Resource managers answered a questionnaire theoretically based on the Human System Audit model. Results showed that the existence of a strategic plan for the normalization of disability in the work environment effectively leads to high levels of inclusion. This is especially relevant for those organizations that have not adapted the systems of training, professional development and internal communication to people with disabilities. The added value and newness of this research lies in bringing empirical evidence on the role of a strategic plan to normalize disability in the work environment, a policy with an internal- and external-focus, as a diversity strategy roadmap in the framework of an inclusive culture.     

A characterization of equilibria in the Groves–Ledyard mechanism

In this paper, we characterize all interior and boundary equilibria of the Groves–Ledyard mechanism for a large class of economies and determine their stability properties. We show that the mechanism admits three types of equilibria: a symmetric, efficient, stable interior equilibrium, a large set of asymmetric, efficient, unstable, interior equilibria, and a large set of asymmetric, inefficient, stable boundary equilibria. We further show that asymmetric equilibria fail to exist for large values of the punishment parameter or if the message space is bounded sufficiently. The boundary equilibria previously had not been located nor had the instability of the asymmetric equilibria been known. Interestingly, the stability of the symmetric equilibrium rests on two dynamics that individually produce instability.     

Pure and randomized equilibria in the stochastic von Neumann–Gale model

The paper examines the problem of the existence of equilibrium for the stochastic analogue of the von Neumann–Gale model of economic growth. The mathematical framework of the model is a theory of set-valued random dynamical systems defined by positive stochastic operators with certain properties of convexity and homogeneity. Existence theorems for equilibria in such systems may be regarded as generalizations of the Perron–Frobenius theorem on eigenvalues and eigenvectors of positive matrices. The known results of this kind are obtained under rather restrictive assumptions. We show that these assumptions can be substantially relaxed if one allows for randomization. The main result of the paper is an existence theorem for randomized equilibria. Some special cases (models defined by positive matrices) are considered in which the existence of pure equilibria can be established.     

Building long-term orientation in buyer–supplier relationships: The moderating role of culture

This research investigates buyer–supplier relationships in international markets. Research and practice have shown that buyer–supplier relationships benefit when partners to the relationship exhibit a long-term orientation. The extant literature suggests that a buyer's trust of a supplier and the supplier's performance affect the buyer's long-term orientation toward the relationship. We propose that the relative effects of trust and performance on long-term orientation are moderated by culture – specifically the individualism/collectivism dimension. Hypotheses are tested on data from two individualist and two collectivist cultures, using responses from over 600 purchasing professionals in the United States, Anglophone Canada, Francophone Canada and Mexico. Taken together, empirical findings suggest that cultural differences warrant consideration in developing successful purchasing strategies.     

What moves housing markets: A variance decomposition of the rent–price ratio

We apply the dynamic Gordon growth model to the housing market in 23 US metropolitan areas, the four Census regions, and the nation from 1975 to 2007. The model allows the rent–price ratio at each date to be split into the expected present discounted values of rent growth, real interest rates, and a housing premium over real rates. We show that housing premia are variable and forecastable and account for a significant fraction of rent–price ratio volatility at the national and local levels, and that covariances among the three components damp fluctuations in rent–price ratios. Thus, explanations of house-price dynamics that focus only on interest rate movements and ignore these covariances can be misleading. These results are similar to those found for stocks and bonds.     

Moderation by goal commitment of the feedback–performance relationship: Theoretical explanation and preliminary study

This paper presents goal commitment as one stage of a multidimensional goal striving process that affects feedback acquisition, processing, and use during the achievement of performance goals. Specifically, this paper argues that higher goal commitment leads to more effective acquisition, processing, and use of feedback that in turn fosters higher performance than does lower goal commitment. To provide a preliminary test of this proposition, data from an earlier field study conducted by the author and colleagues [J. Occup. Organ. Psychol. 72 (1999) 107] were used to examine the moderating effects of goal commitment on the relationship between perceived task feedback amount and work performance of 196 rehabilitation counselors. Results were consistent with this proposed interaction, as perceived task feedback amount had a positive linear relationship with work performance for higher goal commitment rehabilitation counselors and a negative linear relationship with performance for lower goal commitment counselors. The discussion urges researchers to broaden their views of goal commitment beyond the goal difficulty–performance relationship and to devote more attention to moderators of the feedback–performance relationship. Directions for future research and practical implications are also discussed.     

Mortality Forecasting and Trend Shifts: an Application of the Lee–Carter Model to Swedish Mortality Data*

In this paper we examine how the Lee–Carter model fares with Swedish data for the period 1901–2001 and for segments of this period. We have choosen to censor ages less than age 40 as those ages only are of marginal interest to the forecast. At age 40 some 98 to 99 percent of the birth cohorts are survivors. In the study we only consider the unweighted K¹ estimates. The Lee–Carter model provides very good fits to the data. When splitting up the base period there seems to be an interaction beween the age and time components of the model. In order to deal with the different phases of falling mortality for males and females possibly one should choose the past 25 years as a base in the model. Selecting the base period is however a judgmental issue depending on the main focus of the forecast. Is it long‐term, short‐term or, as in Sweden, a combination of both.?     

Purchasing strategies in the Kraljic matrix—A power and dependence perspective

Kraljic's purchasing portfolio approach has inspired many academics to undertake further research into purchasing portfolio models. Refined models typically recommend one purchasing strategy for each portfolio quadrant. Yet, it has been shown that purchasers make a clear distinction between alternative purchasing strategies within each quadrant. The fundamental assumption of portfolio models seems to be that differences in power and dependence between buyers and suppliers exist. Still, little is known about how these concepts influence the choice for a specific purchasing strategy. In this paper, ‘relative power’ and ‘total interdependence’ for a number of portfolio-based purchasing strategies have been quantified empirically, using data from a comprehensive survey among Dutch purchasing professionals. The survey data largely confirmed the hypotheses that were deduced from the literature.     

Dose–response modelling for bivariate covariates with and without a spike at zero: theory and application to binary outcomes

In epidemiology and clinical research, there is often a proportion of unexposed individuals resulting in zero values of exposure, meaning that some individuals are not exposed and those exposed have some continuous distribution. Examples are smoking or alcohol consumption. We will call these variables with a spike at zero (SAZ). In this paper, we performed a systematic investigation on how to model covariates with a SAZ and derived theoretical odds ratio functions for selected bivariate distributions. We consider the bivariate normal and bivariate log normal distribution with a SAZ. Both confounding and effect modification can be elegantly described by formalizing the covariance matrix given the binary outcome variable Y. To model the effect of these variables, we use a procedure based on fractional polynomials first introduced by Royston and Altman (1994, Applied Statistics 43: 429–467) and modified for the SAZ situation (Royston and Sauerbrei, 2008, Multivariable model‐building: a pragmatic approach to regression analysis based on fractional polynomials for modelling continuous variables, Wiley; Becher et al., 2012, Biometrical Journal 54: 686–700). We aim to contribute to theory, practical procedures and application in epidemiology and clinical research to derive multivariable models for variables with a SAZ. As an example, we use data from a case–control study on lung cancer.     

Catching-up and inflation in Europe: Balassa–Samuelson, Engel's Law and other culprits

This study analyses the impact of economic catching-up on annual inflation rates in the European Union with a special focus on the new member countries of Central and Eastern Europe. Using an array of estimation methods, we show that the Balassa-Samuelson effect is not an important driver of inflation rates. By contrast, we find that the initial price level and regulated prices strongly affect inflation outcomes in a nonlinear manner and that the extension of Engel's Law may hold during periods of very fast growth. We interpret these results as a sign that price level convergence comes from goods, market and non-market service prices. Furthermore, we find that the Phillips curve flattens with a decline in the inflation rate, that inflation is more persistent and that commodity prices have a stronger effect on inflation in a higher inflation environment.     

A family of empirical likelihood functions and estimators for the binary response model

The minimum discrimination information principle is used to identify an appropriate parametric family of probability distributions and the corresponding maximum likelihood estimators for binary response models. Estimators in the family subsume the conventional logit model and form the basis for a set of parametric estimation alternatives with the usual asymptotic properties. Sampling experiments are used to assess finite sample performance.     

Evaluation of supplier capability and performance: A method for supply base reduction

Development of partnership with suppliers is widely recognised today as a potent tool for supply chain improvement. To develop an effective partnership, it is necessary to have a small supply base and an effort to reduce the supply base to a manageable level. Despite its overwhelming importance, models of supply base reduction are rare. Supplier sorting methods, used for pre-selection of suppliers and sometimes seen as methods for supply base reduction, have limitations ranging from (1) requirement of an exhaustive database of historical information (case-based reasoning), (2) inability to predefine the number of elements in a cluster (cluster analysis) and (3) inability to identify suppliers who are both highly capable as well as high performers (data envelopment analysis). In the present work, we develop a systematic framework for carrying out the supply base reduction process. The study assumes two important dimensions of suppliers—performance and capability. Performance of a supplier represents short-term effects on the achievement of supply chain objectives while supplier capability indicates long-term effects. Many of the performance and capability factors are imprecise in nature. In order to account for the imprecision involved in numerous subjective characteristics of suppliers, we use fuzzy set approach to measure the imprecision of these factors and rank a potential list of suppliers against their performance and capability. We then display their ranks in a ‘capability–performance matrix’ that helps a decision maker arrange the suppliers in decreasing order of preference. The desired numbers of suppliers are finally selected on the basis of this ordered list. The suggested framework will be of immense help to the practising managers in reducing the supply base—a prerequisite for building a strong supplier partnership and developing an effective supply chain.     

Inside the queue:: hypercongestion and road pricing in a continuous time–continuous place model of traffic congestion

This paper develops a continuous-time–continuous-place dynamic economic model of traffic congestion, based on car-following theory. The model integrates two archetype congestion technologies used in the economics literature: ‘static flow congestion’ and ‘dynamic bottleneck congestion.’ With endogenous departure times and a bottleneck along the route, ‘hypercongestion’ arises as a dynamic equilibrium phenomenon on the upstream road segment. Congestion tolls based on an intuitive dynamic and space-varying generalization of the standard Pigouvian tax rule can hardly be improved upon. A naïve application of a toll schedule based on Vickrey's bottleneck model performs much worse and reduces welfare in the numerical model.     

A review of the literature on environmental innovation management in SMEs: implications for public policies

The aim of this article is to collect and make up the most important contributions in the economic literature in relation to the special characteristics of the management of the environmental innovation in the SMEs. Specifically, we want to show their strengths and weaknesses in order to make up the main conclusions of these analyses with the literature in relation to the way Public Administrations face this situation. The scarce development in the SMEs in respect to their environmental strategy may be a consequence of the links among some of the following factors: limited financial resources, the type of organizational structure, a little influence of the strategic adaptation competence against the changes in the SMEs, the managers’ scarce environmental training and short term orientation, the staff’s scarce environmental awareness and training, the status of the environmental issues in the company, the SMEs’ lower ability to obtain highly radical innovations, the scarce influence of manufacturing process flexibility in the most advanced states of the environmental strategy in the SMEs and their lack of relation ability with external stakeholders—very important in the success of the most advanced environmental approaches. Besides, the lack of regulation neutrality must be added as a key difference among companies of different sizes. So specific actions seem be necessary, such as technological advice and awareness, and training programs in order to cooperate with external stakeholders.     

城镇化背景下侗族乡土聚落的保护与发展策略

通过对典型案例的剖析,总结了侗族乡土聚落演进中的聚落空间异化、聚落管理弱化与聚落更新"现代化"等共同趋势,提出快速城镇化带来的产业变化、农村人口流动以及生活观念转变是影响侗族乡土聚落聚居模式的深层原因。进而通过把保护和发展视角从传统的注重实体和空间的层面扩展到经济和社会层面,建立了调整产业结构、健全聚落管理、重构聚落空间的乡土聚落保护与发展战略架构,并阐述了具体策略。     

试论我国反家庭暴力立法的缺失与完善

家庭暴力在世界范围内都是较为普遍存在的社会问题。近年来,中国反家庭暴力立法工作正逐步深入和加强,但在实施过程中仍然出现诸多问题亟待解决与完善。本文分析了我国反家庭暴力立法现状及不足,进而结合我国国情提出完善反家庭暴力立法的具体建议。