Forecasting and turning point predictions in a Bayesian panel VAR model

We provide methods for forecasting variables and predicting turning points in panel Bayesian VARs. We specify a flexible model, which accounts for both interdependencies in the cross section and time variations in the parameters. Posterior distributions for the parameters are obtained for hierarchical and for Minnesota-type priors. Formulas for multistep, multiunit point and average forecasts are provided. An application to the problem of forecasting the growth rate of output and of predicting turning points in the G-7 illustrates the approach. A comparison with alternative forecasting methods is also provided.     

《护理学导论》教学中提高学生参与的方法研究

目的:探讨在《护理学导论》教学中提高学生参与的方法。方法选取我校2009级高职护理110名学生为研究对象,采用随机抽样原则,将其分为实验组和对照组。其中实验组含54名学生,采用多种方法让学生参与教学;对照组含56名学生,采用传统教学方法。结果实验组学习兴趣,语言表达能力和期末考核成绩及技能考核成绩均明显由于对照组。结论:在教学中采用多种方法让学生参与教学能提高教学效果。     

QUALITATIVE AND MIXED‐METHODS RESEARCH IN ECONOMICS: SURPRISING GROWTH,PROMISING FUTURE

Qualitative research in economics has traditionally been unimportant compared to quantitative work. Yet there has been a small explosion in use of quantitative approaches in the past 10–15 years, including ‘mixed‐methods’ projects which use qualitative and quantitative methods in combination. This paper surveys the growing use of qualitative methods in economics and closely related fields, aiming to provide economists with a useful roadmap through major sets of qualitative methods and how and why they are used. We review the growing body of economic research using qualitative approaches, emphasizing the gains from using qualitative‐ or mixed‐methods over traditional ‘closed‐ended’ approaches. It is argued that, although qualitative methods are often portrayed as less reliable, less accurate, less powerful and/or less credible than quantitative methods, in fact, the two sets of methods have their own strengths, and how much can be learned from one type of method or the other depends on specific issues that arise in studying the topic of interest. The central message of the paper is that well‐done qualitative work can provide scientifically valuable and intellectually helpful ways of adding to the stock of economic knowledge, especially when applied to research questions for which they are well suited.     

Emergent clustering methods for empirical OM research

To date, the vast majority of cluster analysis applications in OM research have relied on traditional hierarchical (e.g., Ward's algorithm) and nonhierarchical (e.g., K-means algorithms) methods. Although these venerable methods should continue to be employed effectively in the OM literature, we also believe there is a significant opportunity to expand the scope of clustering methods to emergent techniques. We provide an overview of some alternative clustering procedures (including advantages and disadvantages), identify software programs for implementing them, and discuss the circumstances where they might be employed gainfully in OM research. The implementation of emergent clustering methods in the OM literature should enable researchers to offer implications for practice that might not have been uncovered with traditional methods.     

Solving DSGE models with perturbation methods and a change of variables

This paper explores the application of the changes of variables technique to solve the stochastic neoclassical growth model. We use the method of Judd [2003. Perturbation methods with nonlinear changes of variables. Mimeo, Hoover Institution] to change variables in the computed policy functions that characterize the behavior of the economy. We report how the optimal change of variables reduces the average absolute Euler equation errors of the solution of the model by a factor of three. We also demonstrate how changes of variables correct for variations in the volatility of the economy even if we work with first-order policy functions and how we can keep a linear representation of the laws of motion of the model if we use a nearly optimal transformation. We discuss how to apply our results to estimate dynamic equilibrium economies.     

Mixed methods studies in entrepreneurship research: Applications and contributions

Mixed methods research is becoming an increasingly popular approach in several fields. However, its application in the field of entrepreneurship has not been studied. The authors reviewed the use of mixed methods research in three entrepreneurship journals and two leading generalistic journals that publish entrepreneurship research, examining the main purposes and designs. A total of 955 articles were reviewed and 81 mixed methods studies were identified. The analysis of these articles revealed opportunities associated with the application of this approach. Mixed methods may help to improve entrepreneurship research addressing challenges emphasized in earlier studies. Suggestions on why and how to use mixed methods research are offered, and recommendations are provided to guide future mixed methods studies to advance our understanding of the entrepreneurial phenomenon.     

A typology of mixed methods research designs

The mixed methods paradigm is still in its adolescence, and, thus, is still relatively unknown and confusing to many researchers. In general, mixed methods research represents research that involves collecting, analyzing, and interpreting quantitative and qualitative data in a single study or in a series of studies that investigate the same underlying phenomenon. Over the last several years, a plethora of research designs have been developed. However, the number of designs that currently prevail leaves the doctoral student, the beginning researcher, and even the experienced researcher who is new to the field of mixed methods research with the challenge of selecting optimal mixed methods designs. This paper presents a three-dimensional typology of mixed methods designs that represents an attempt to rise to the challenge of creating an integrated typology of mixed methods designs. An example for each design is included as well as a notation system that fits our eight-design framework. This paper won the James E. McLean outstanding paper award.     

内燃机设计课程教学改革的探索与实践

针对热能与动力工程专业的内燃机设计课程,从教学方式和考核方式两方面,提出了若干改革的思路和设想。     

Solving the multi-country real business cycle model using ergodic set methods

We use the stochastic simulation algorithm, described in Judd et al. (2009), and the cluster-grid algorithm, developed in Judd et al. (2010a), to solve a collection of multi-country real business cycle models. The following ingredients help us reduce the cost in high-dimensional problems: an endogenous grid enclosing the ergodic set, linear approximation methods, fixed-point iteration and efficient integration methods, such as non-product monomial rules and Monte Carlo integration combined with regression. We show that high accuracy in intratemporal choice is crucial for the overall accuracy of solutions and offer two approaches, precomputation and iteration-on-allocation, that can solve for intratemporal choice both accurately and quickly. We also implement a hybrid solution algorithm that combines the perturbation and accurate intratemporal-choice methods.     

Mixed Methods Studies in Environmental Management Research: Prevalence,Purposes and Designs

Mixed methods research, that is, the combined use of quantitative and qualitative methods in the same study, is a popular approach in several fields. However, its use in the field of environmental management and sustainable development has not been examined. The authors review the application of mixed methods research in the journal Business Strategy and the Environment in the last ten years. A total of 340 articles have been read and reviewed, and 26 mixed methods studies have been identified. The main purposes and mixed methods designs are examined. Suggestions on why and how to use mixed methods research are offered, and recommendations are provided to guide future mixed methods studies to advance our understanding of environmental management topics. Copyright © 2014 John Wiley & Sons, Ltd and ERP Environment     

Stationary Markovian equilibrium in altruistic stochastic OLG models with limited commitment

We introduce a new class of infinite horizon altruistic stochastic OLG models with capital and labor, but without commitment between the generations. Under mild regularity conditions, for economies with either bounded or unbounded state spaces, continuous monotone Markov perfect Nash equilibrium (henceforth MPNE) are shown to exist, and form an antichain. Further, for each such MPNE, we can also construct a corresponding stationary Markovian equilibrium invariant distribution. We then show for many versions of our economies found in applied work in macroeconomics, unique MPNE exist relative to the space of bounded measurable functions. We also relate all of our results to those obtained by promised utility/continuation methods based upon the work of Abreu et al. (1990). As our results are constructive, we can provide characterizations of numerical methods for approximating MPNE, and we construct error bounds. Finally, we provide a series of examples to show the potential applications and limitations of our results.     

Specification of Distance Functions Using Semi- and Nonparametric Methods with an Application to the Dynamic Performance of Eastern and Western European Air Carriers

In this paper we examine the productive performance of a group of three East European carriers and compare it to thirteen of their West European competitors during the period 1977–1990. We first model the multiple output/multiple input technology with a stochastic distance frontier using recently developed semiparametric efficient methods. The endogeneity of multiple outputs is addressed in part by introducing multivariate kernel estimators for the joint distribution of the multiple outputs and potentially correlated firm random effects. We augment estimates from our semiparametric stochastic distance function with nonparametric distance function methods, using linear programming techniques, as well as with extended decomposition methods, based on the Malmquist index number. Both semi- and nonparametric methods indicate significant slack in resource utilization in the East European carriers relative to their Western counterparts, and limited convergence in efficiency or technical change between them. The implications are rather stark for the long run viability of the East European carriers in our sample.     

中国管理会计研究如何走向世界

从研究主题、理论基础与研究方法三个主要方面探讨了管理会计研究面临的关键性问题。进而采用文献回顾对《会计研究》和JMAR在1996-2006共11年发表的管理会计论文进行了统计分析,进一步验证了前述分析。最后,为中国管理会计研究如何走向世界提供了建设性意见。     

浅析国内主要城市标准化工作激励政策

文章从区域分布、内容、评价方式等方面介绍了周内主要城市标准化工作的激励政策,并对典型城市进行了案例分析,以期对各地出台新的激励政策提供借鉴和启示。     

Interior point methods, a decade after Karmarkar—a survey, with application to the smallest eigenvalue problem

The introduction of Karmarkar's polynomial algorithm for linear programming (LP) in 1984 has influenced wide areas in the field of optimization. While in the 1980s emphasis was on developing and implementing efficient variants of interior point methods for LP, the 1990s have shown applicability to certain structured nonlinear programming and combinatorial problems. We will give a historical account of the developments and illustrate the typical results by analyzing a new method for computing the smallest eigenvalue of a matrix. We formulate this latter problem as a so-called semidefinite optimization problem. Semidefinite optimization has recently gained much attention since it has a lot of applications in various fields (like control and system theory, combinatorial optimization, algebra, statistics, structural design) and semidefinite problems can be efficiently solved with interior point methods.     

Supplier selection with rank reversal in public tenders

For supplier selection in the public sector, the Weighted Sum Model is often used in combination with relative scoring methods that allow rank reversal. With rank reversal we refer to a changed order in the ranking of bids leading to a new winner, after removing or adding a non-optimal bid that does not win the original tender. In practice, an important reason indicated by practitioners for using methods that allow rank reversal is that it would rarely occur in practice. Based on an analysis of 303 Dutch public tenders, this research shows this is not true. In about 1 out of 5 the tenders, rank reversal occurs after adding non-optimal fictional bids to tenders that do not have quality thresholds. After removing bids, the rate is about 1 out of 40 if a curved relative scoring method is used. In addition, the research shows that rank reversal rates increase when (i) there is no quality threshold, (ii) the number of bids increases, (iii) bid price variance increases, and (iv) price weights are not very low or high. We argue that relative scoring methods that allow rank reversal should not be used in public procurement, or otherwise only in exceptional cases, as it conflicts with public procurement principles and leads to reduced overall bid value.     

浅谈中职教育的教学改革

职业教育的目的是培养实用型人才,我国中职教育存在着很多问题,如教育方法落后,教师队伍的素质不尽如意等。这些都是职业教育健康发展有待解决问题。我们必须更新观念,改革课程设置和教学内容,创新教学方法,加强教师培训。     

Seat allocation distributions and seat biases of stationary apportionment methods for proportional representation

In a proportional representation system, apportionment methods are used to round the vote proportion of a party to an integer number of seats in parliament. Assuming uniformly distributed vote proportions, we derive the seat allocation distributions for stationary divisor methods. An important characteristic of apportionment methods are seat biases, that is, expected differences between actual seat numbers and ideal shares of seats, when the parties are ordered from largest to smallest. We obtain seat bias formulas for the stationary divisor methods and for the quota method of greatest remainders.Acknowledgement. We thank Friedrich Pukelsheim for many fruitful discussions.Received March 2004     

Revisiting the Quantitative-Qualitative Debate: Implications for Mixed-Methods Research

Health care research includes many studies that combine quantitative and qualitative methods. In this paper, we revisit the quantitative-qualitative debate and review the arguments for and against using mixed-methods. In addition, we discuss the implications stemming from our view, that the paradigms upon which the methods are based have a different view of reality and therefore a different view of the phenomenon under study. Because the two paradigms do not study the same phenomena, quantitative and qualitative methods cannot be combined for cross-validation or triangulation purposes. However, they can be combined for complementary purposes. Future standards for mixed-methods research should clearly reflect this recommendation.     

Quasi Score is more Efficient than Corrected Score in a Polynomial Measurement Error Model

We consider a polynomial regression model, where the covariate is measured with Gaussian errors. The measurement error variance is supposed to be known. The covariate is normally distributed with known mean and variance. Quasi score (QS) and corrected score (CS) are two consistent estimation methods, where the first makes use of the distribution of the covariate (structural method), while the latter does not (functional method). It may therefore be surmised that the former method is (asymptotically) more efficient than the latter one. This can, indeed, be proved for the regression parameters. We do this by introducing a third, so-called simple score (SS), estimator, the efficiency of which turns out to be intermediate between QS and CS. When one includes structural and functional estimators for the variance of the error in the equation, SS is still more efficient than CS. When the mean and variance of the covariate are not known and have to be estimated as well, one can still maintain that QS is more efficient than SS for the regression parameters.