Multilevel theory and the underspecification of multilevel models

This article emphasises the importance of the adequate specification of models of multilevel analysis in accordance with multilevel theories. Until recent times, multilevel theories tried only to explain the direct effect of group characteristics on an individual's characteristic. It seems to be more suited to adopt a more general theoretical approach, in which it is assumed that group characteristics affects individual processes. There a treshold effect and a process effect have to be distinguished. The propositions result in a model specification within the random coefficient model of multilevel analysis. The theory and model recommended are illustrated by means of data of Dar and Resh's (1986) study into social learning environment.     

基于三螺旋的创意城市研究——以苏州工业园区为例

创意经济是世界经济社会高度发展的产物,创意产业在国家或城市经济发展中所占的比重将会越来越大。Florida的3T理论认为技术、人才和宽容是创意城市必不可少的三要素,三螺旋创新模式的正确运用将进一步增强创意城市三要素,提高城市创意指数,从而为中国发展创意城市提供理论依据。     

Constructing and using a multiplicative model of the impact of societal changes on violent crime

This study aims at exploring the possibilities of using a multiplicative model when explaining the impact of societal changes on violent crime in Swedish municipalities. A theory of criminality in municipalities is presented which is founded on an analysis of individual decision-making on the commission of crimes. According to this theory, the level of criminality in a given municipality is determined by two average properties for the individuals who stay there — the average amount of occasions when the circumstances are favorable to the commission of crimes and the average probability of committing a crime on such an occasion. On the basis of the theory, a model of the relationship between criminality and specified characteristics of the municipality has been constructed. Criminality is assumed to be the product of a range of factors, each of which is a linear function of current and earlier values of a municipality characteristic. Using this model, the relationship between changes in the level of criminality and variables measuring independent characteristics at different points in time has been empirically analyzed. The data used are of register type and refer primarily to the years 1970, 1975, and 1980. Model parameters are estimated by a least-square fit. It is found that the multiplicative model explains much more of the variance in changes in the level of criminality than does the linear model including the same municipality characteristics. In the multiplicative model. independent variables obtain weights that give a different picture of the causal processes that affect criminality as compared with the linear model.     

Catholicism and Economics: Towards a “Deeper Reflection on the Nature of the Economy and its Purposes”

Many of the problems neoclassical economic theory has in explaining the real world stem from its narrow view of human nature—the “rational economic man” model, which forces economists to exclude social and historical context. Every social theory starts with a view of human nature that necessarily comes from outside the social sciences. Philosophy and theology are the sources of our ideas about the nature of humans, society, and the good that humans pursue. Catholic Social Thought has a rich understanding of human nature, which includes both the uniqueness of persons and their inherently social nature. Starting from this foundation, economists can develop a deeper understanding of the nature of the economy. Catholic Social Thought does not offer a different economic theory or model, but it does provide an alternative vision upon which more adequate and realistic economic theories can be constructed.     

Chaos theory and social science: A methodological analysis

This article investigates the relevance of chaos theory for social science. The application of chaos models in the analysis of social phenomena is accompanied by some important scientific problems. First, whether observations of social phenomena are generated by nonlinear dynamics cannot be ascertained beyond considerable doubt, especially when these observations contain measurement errors; i.e., there is a problem of external validity. Secondly, and more important, as a theory of irregular cyclical social behaviour is lacking, inductive-statistical theoryformation about such behaviour, which is based on fitting a mathematical model of chaos to observations of social phenomena, is impossible unless additional information is used concerning the context and circumstances wherein the social phenomena occur; i.e., the internal validity of any theoretical explanation that is derived from only a fitted mathematical model (of chaos) cannot be assessed. So, research into the suggestion derived from mathematical chaos theory that irregular cycles may be present in the development of social phenomena over time requires theory-formation about irregular cyclical social behaviour on the basis of established theoretical insights and empirical evidence instead of fitting sophisticated mathematical models of chaos to observations of social phenomena.     

“控制工程基础”教学模式探讨

针对控制工程基础课程具有概念抽象、内容复杂、多学科交叉、数学运算量大、工程实用性强、课时少等特点,提出了该课程理论与实验相结合的渐进式教学模式,即理论、实践、模拟仿真。在该模式下开展综合性实验,学生能够加深对理论知识的理解并提高运用知识分析解决问题实际的能力。     

Statistical aspects of simulation: an updated survey*

Abstract Practical statistical techniques for the design and analysis of simulation experiments are presented. These techniques are relevant in both discrete and continuous, deterministic and stochastic simulation. To generalize and interpret the simulation output the analyst can use regression analysis. This analysis allows for interactions among factors. Actually the regression model provides either a first-order or a second-order approximation to the complicated simulation model. To decide which system variants (parameter combinations) should be simulated, the analyst may apply experimental design theory. This theory makes the exploration of the simulated system much more efficient and more thorough. In the preliminary phase of the simulation experimentation special screening designs can be used to investigate hundreds of factors in relatively few runs. In stochastic simulation additional problems arise. There are several approaches for determining how to initialize a simulation run and how long to continue that run. These approaches result in a confidence interval for the estimated response. Both steady-state and transient behavior are examined. Special variance reduction techniques are briefly discussed; the use of common random numbers (identical seeds) is discussed in more detail.     

An Analytic Network Process model for financial-crisis forecasting

We discuss and develop an imbalance-crisis turning point model to forecast the likelihood of a financial crisis based on an Analytic Network Process framework. The Analytic Network Process (ANP) is a general theory of relative measurement used to derive composite-priority-ratio scales from individual-ratio scales that represent relative influence of factors that interact with respect to control criteria. Through its supermatrix, which is composed of matrices of column priorities, the ANP framework captures the outcome of dependence and feedback within and between clusters of explanatory factors. We argue that our framework is more flexible and is more comprehensive than traditional methods and previous models. We illustrate how the ANP model would be implemented for forecasting the probability of crises.     

Robustness of normal theory statistics in structural equation models*

A condition is given by which optimal normal theory methods, such as the maximum likelihood methods, are robust against violation of the normality assumption in a general linear structural equation model. Specifically, the estimators and the goodness of fit test are robust. The estimator is efficient within some defined class, and its standard errors can be obtained by a correction formula applied to the inverse of the information matrix. Some special models, like the factor analysis model and path models, are discussed in more detail. A method for evaluating the robustness condition is given.     

A probability model of the housing market based on quasi-classical considerations

This paper sets out a simple probability model for explaining locational patterns and trip-making in urban housing markets. As a prerequisite to formulating the model, the classical theory of residential location based on consumer theory is briefly outlined, and the difficulties of using such theory in an operational context are discussed. A more flexible approach, based on certain classical considerations involving rents, travel costs, and incomes is introduced and a model of the housing market is formulated using a probability-maximizing method. The model is then applied to residential location in the Reading sub-region, and tests of the model reveal that its performance in statistical terms is reasonable. In conclusion, certain possibilities for embedding the model into a more comprehensive modelling framework are explored.     

People,practice, and technology: Restoring Giddens' broader philosophy to the study of information systems

This paper argues that practice-based management and IS literature has tended to portray a voluntaristic account of human agency that downplays the contribution to emergent social outcomes of more deeply rooted psychological dimensions of the human condition. Within the IS research community, this tendency is exemplified in work using Giddens' structuration theory, which, whilst acknowledging the importance of human interpretive properties, has foregrounded cognitive aspects to interpretation at the expense of important non-cognitive ingredients such as affect and biographical identity. These non-cognitive ingredients are less amenable for study using the structurational model, but receive comprehensive treatment elsewhere in Giddens' work. Accordingly, it is argued that a useful direction for future theory development would be to seek a more balanced account of humans' co-constitutive relationship with technology in practice. This could be achieved by supplementing the structurational perspective, with its primary focus on emergent social structure, with a more explicit engagement with Giddens' broader concern with emergent biographical structure. An initial integrative framework is offered as a first step in this direction.     

Health care facility planning: some developmental considerations.

A model of the provision of health care facilities is outlined. This model is based on a framework developed in central place theory and is concerned with the scale, frequency and service area structure of health care facilities. Certain modifications to the model are proposed and this provides a framework for dealing with the problem of adjustment in systems of service provision. Three types of adjustment, all involving different degrees of centralization, are considered. Each type of adjustment results in a particular modification to the spatial structure of the hierarchical system. Consideration is then briefly given to a number of ways in which this general approach may be made more realistic, in order to deal with actual systems of service provision.     

On the estimation of the parameters for the Littlewood model in software reliability

A very well-known model in software reliability theory is that of Littlewood (1980). The (three) parameters in this model are usually estimated by means of the maximum likelihood method. The system of likelihood equations can have more than one solution. Only one of them will be consistent, however. In this paper we present a different, more analytical approach, exploiting the mathematical properties of the log-likelihood function itself. Our belief is that the ideas and methods developed in this paper could also be of interest for statisticians working on the estimation of the parameters of the generalised Pareto distribution. For those more generally interested in maximum likelihood the paper provides a 'practical case', indicating how complex matters may become when only three parameters are involved. Moreover, readers not familiar with counting process theory and software reliability are given a first introduction.     

Is gravity linear?

Despite the solid theoretical foundation on which the gravity model of bilateral trade is based, empirical implementation requires several assumptions which do not follow directly from the underlying theory. First, unobserved trade costs are assumed to be a (log‐)linear function of observables. Second, the effects of trade costs on trade flows are assumed to be constant across country pairs. Maintaining consistency with the underlying theory, but relaxing these assumptions, we estimate gravity models—in levels and logs—using two data sets via nonparametric methods. The results are striking. Despite the added flexibility of the nonparametric models, parametric models based on these assumptions offer equally or more reliable in‐sample predictions and out‐of‐sample forecasts in the majority of cases, particularly in the levels model. Moreover, formal statistical tests fail to reject either parametric functional form. Thus, concerns in the gravity literature over functional form appear unwarranted, and estimation of the gravity model in levels is recommended. Copyright © 2008 John Wiley & Sons, Ltd.     

An alternative test of the hedonic theory of housing markets

In this paper the hedonic theory of housing markets is used to generate a multinomial logit model of household behavior in an urban housing market. Application of hedonic theory to housing markets is by now fairly familiar and a link to multinomial logit has also been established. However, by emphasizing more heavily the bid price interpretation of hedonic theory, this paper develops a new connection to econometric estimation that essentially involves running the usual logit equations in reverse. One advantage of this approach is that the link between the logit equations and hedonic theory involves bid price rather than utility functions, and this in turn permits the empirical results to be given an extremely clear interpretation. Furthermore, in contrast to the standard logit model, the extreme value distribution required to justify the estimation technique emerges endogenously as part of the analysis.     

循环物流中再制造技术应用的理论研究

随着物流技术的不断发展,再制造技术逐渐引起了更多的关注,如何构建高效的再制造系统模型是实现循环经济目标的关键问题。文章从再制造技术的理论出发,综合考虑各项影响因素,指出再制造系统管理的重点环节。最后根据柔性制造系统引入了柔性再制造系统理论．作为再制造系统建设的方向。     

A Brief Survey of Modern Optimization for Statisticians

Modern computational statistics is turning more and more to high‐dimensional optimization to handle the deluge of big data. Once a model is formulated, its parameters can be estimated by optimization. Because model parsimony is important, models routinely include non‐differentiable penalty terms such as the lasso. This sober reality complicates minimization and maximization. Our broad survey stresses a few important principles in algorithm design. Rather than view these principles in isolation, it is more productive to mix and match them. A few well‐chosen examples illustrate this point. Algorithm derivation is also emphasized, and theory is downplayed, particularly the abstractions of the convex calculus. Thus, our survey should be useful and accessible to a broad audience.     

Cultural Values and Social Planning: A Control Theory Approach to Satisfying a Social Welfare Criterion

A bstract . A method of social planning is presented which can be used to fulfill a social welfare criterion with normative values. The purpose is to show how a social welfare model which includes cultural norms can be optimized using classical control theory. Current literature stresses the importance of incorporating social indicators in welfare economics. Given a social welfare function which actively includes a hierarchy of cultural values , control theory can be used to set social policy to reach social goals. The approach is to define a set of desired cultural norms at some future time and then determine the social policy necessary to reach this state. Control theory is used to find the social plan consistent with attaining the set of desired values.     

THE RESURGENCE OF INVENTORY RESEARCH: WHAT HAVE WE LEARNED?

Abstract. Recent empirical and theoretical research on business inventories is surveyed and critically evaluated. While most inventory research has had macroeconomic motivations, we focus on its microtheoretic basis and on potential conflicts between theory and evidence. The paper asks two principal questions. First, how can inventories, which are allegedly used by firms to stabilize production, nonetheless be a destabilizing factor at the macroeconomic level? Second, why, if firms are following the production-smoothing model, is production more variable than sales in many industries? We suggest that the so-called (S,s) model may help answer both questions.