Social networks,mass media and public opinions

Our opinions and ideas are shaped by what our friends said and what we read or watched on mass media. In this paper, we propose a concise and analyzable model to study the effects of mass media modeled as an applied external field, and social networks on public opinions based on the multi-state voter model, and a tuned parameter can control the relative intensity of the effects of mass media and social networks. We consider a generalized scenario where there exist committed or stubborn agents in the networks whose opinions are not affected by their friends or mass media. We find that the fraction of each opinion will converge to a value which only relates to the fractions and degrees of stubborn agents, and the relative intensity between media and network effects. The final agents with media opinion, except the stubborn agents, also include the increment produced by the internal impact of social networks and that caused by the external impact of media. Interestingly the second increment is composed of two parts, one is from the media effect when there are no interactions between agents and the other is from the influence of media on agent opinions caused by social network structure. That is the interactions among agents within social networks can amplify media influence. Finally we also discuss several extensions to the dynamics model which consider more realistic scenarios.     

A market model of analysts’ opinions to explain changes in the dispersion of opinions

The demand for and supply of analysts’ opinions in this model yield an equilibrium that demonstrates how the information content of the opinions reacts to changes in exogenous parameters. The model also shows how changes in the parameters make analysts’ opinions more or less dispersed; for example, a decline in investor risk aversion, a decrease in market volatility, and an increase in information costs can lead to analysts’ opinions becoming more similar. Recognizing how exogenous factors can affect the supply and demand of analysts’ opinions gives additional insights into questions concerning what may appear to be herd behavior by analysts and also the relationship between forecast dispersion and information content. (JEL: G29, C71)     

组团式结构城市的轨道线网合理规模

本文在组团式城市空间结构及其交通特点与轨道交通功能分析基础上 ,提出了宏观定性控制与微观定量分析相结合的组团式城市轨道线网规模及线网结构的方法。     

Disruptive technology adoption,particularities of clustered firms

ABSTRACT

This article explores to what extent the internal attributes of a clustered firm influence its capacity to adopt disruptive innovations. A multidimensional approach to the absorptive capacity (ACAP) model is used to distinguish between potential (acquisition and assimilation domains) and realized (transformation and exploitation domains) internal firm capabilities. Our evidence comes from an empirical analysis of the population of firms belonging to the Spanish ceramic tile cluster which have adopted a disruptive innovation – the so-called digital printing technology – on a massive scale. The econometric estimations suggest the relevance of the Exploitation dimension of ACAP for early adoption of a new technology. In contrast, the other dimensions do not seem to play a decisive role when it comes to adopting one novelty earlier than others. In conclusion, and contrary to what was expected for non-clustered firms, the results revealed an uneven effect of the potential and realized domains of ACAP of clustered firms regarding the rate of adoption of distant technologies.     

Semiparametric analysis of clustered survival data under nonparametric frailty

In this article a novel approach to analyze clustered survival data that are subject to extravariation encountered through clustering of survival times is proposed. This is accomplished by extending the Cox proportional hazard model to a frailty model where the cluster-specific shared frailty is modeled nonparametrically. We assume a nonparametric Dirichlet process for the distribution of frailty. In such a semiparametric setup, we propose a hybrid method to draw model-based inferences. In the framework of the proposed hybrid method, the estimation of parameters is performed by implementing Monte Carlo expected conditional maximization algorithm. A simulation study is conducted to study the efficiency of our methodology. The proposed methodology is, thereafter, illustrated by a real-life data on recurrence time to infections in kidney patient.     

基于复杂网络和乘客选择理论醮长三角机场群研究

中国航空运输业正在致力于形成合理的枢纽机场和支线航空的空间布局。本文研究航空机场布局和旅客流量分布的空间不平衡性,以长江三角洲机场密集但整体效率不佳的情况为例,从复杂网络和乘客出行路径选择理论出发,建立出行路径选择优化模型,分析乘客的航空出行路线选择,利用复杂网络中的介数概念说明枢纽机场的中转服务对周边机场的抑制作用。我们采用实际的航空数据进行了计算和模拟,得到了目前长三角地区各机场的介数和带权介数,并举南京为例做了具体分析,最后对今后机场发展和空间布局建设提出了建议。     

Analysis of marginally specified semi-nonparametric models for clustered binary data

Generalized linear mixed models are widely used for analyzing clustered data. If the primary interest is in regression parameters, one can proceed alternatively, through the marginal mean model approach. In the present study, a joint model consisting of a marginal mean model and a cluster-specific conditional mean model is considered. This model is useful when both time-independent and time-dependent covariates are available. Furthermore our model is semi-parametric, as we assume a flexible, smooth semi-nonparametric density of the cluster-specific effects. This semi-nonparametric density-based approach outperforms the approach based on normality assumption with respect to some important features of 'between-cluster variation'. We employ a full likelihood-based approach and apply the Monte Carlo EM algorithm to analyze the model. A simulation study is carried out to demonstrate the consistency of the approach. Finally, we apply this to a study of long-term illness data.     

Assessing the economic knowledge and economic opinions of adults

This study investigates public knowledge of basic economics and public opinion on economic issues. The primary data sources are five national surveys, administered from 1992 to 1999, which contain a rich set of questions to conduct multiple tests and comparisons of the factors that affect economic knowledge and public opinion. As a whole, the results offer significantly stronger evidence of factors that influence knowledge and opinion than is possible from a study of a particular sample of adults using a single set of survey questions.The analysis proceeds in two ways following methods that were originally used with one of the five data sets, a 1992 survey of adults (Walstad, 1997). First, a regression model is specified and estimated with each data set to identify how personal characteristics, general education, course work in economics, income, and political party affect economic knowledge. Second, probit analysis is used to evaluate the effect of economic knowledge on public opinion on selected economic issues after controlling for the above variables. The results from the 1992 data serve as the baseline for comparing the findings across the other surveys.     

对某市廉租房政策的另类思考

本文以某城市近期拟为低收入者大量新建廉租房的住房政策引出问题,从住宅经济学中的过滤理论和某些国家在类似住房政策实施方面的经验这两个角度出发,对此问题进行一些分析,并提出笔者的一些看法:该市此项住房政策可能导致其房地产市场的退化;造成资源的浪费;并带来许多社会问题.     

Teacher opinions regarding the perception management levels of school administrators

The purpose of this research is to determine the levels and use of perception management by school administrators. The study group consists of teachers working in Private Primary School and Secondary Schools affiliated to the Ministry of National Education in Nicosia, the Turkish Republic of Northern Cyprus in the 2016–2017 academic year. The sample of the study is composed of 282 teachers representing the universe selected by the method of easy reachable case sampling. As a means of collecting data in the survey, “Personal Information Form” by Kline (An easy guide to factor analysis, Routledge, New York, 1994) and “Manager Perception Management ent Scale” developed by Uylas (Yönetici Alg? Yönetimi Ölçe?i, Türkiye Ölçme Araçlar? Dizini, 2017a, Okul Yöneticilerinin Sosyal-Duygusal E?itim Liderli?i ve Alg? Yönetimine ?li?kin Ö?retmen Görü?leri, T.C. Abant ?zzet Baysal Üniversitesi, E?itim Bilimleri Enstitüsü, Bolu, 2017b) was used. The obtained data were analyzed in an analysis program. In the research, the values of perception management use levels of managers according to teacher opinions were examined. According to the results and comments obtained from the research, some of the proposals developed for researchers and educators working in the field of education management are as follows. Towards practical; trainings can be given on how school administrators can use perception management for successful perception management practices in educational organizations. In interviews to select school administrators, choosing school administrator with high perception management skills can be prioritized. Towards newstudies; including multidimensional evaluation of all elements of educational organizations such as managers, parents and servants in new researches to be conducted and comparison of teachers ‘and administrators’ views. This study has brought out suggestions that can be implemented in other stages of education.     

Technological change in health care: Why are opinions so divided?

This paper purports to explain the widespread scepticism towards technological change in health care in general and pharmaceutical innovation in particular in the face of very high estimated rates of social return. These estimates are based on observable market prices and quantities, which are used for measuring the additional consumer surplus induced by an innovation. They grossly overstate true surplus due to the effect of insurance, however. For true demand for health care services and hence true surplus depends on the net price a patient is willing to pay, which is a rather small fraction of observed market price. The paper also outlines the conditions under which a health insurer would welcome a pharmaceutical innovation.     

Expert opinions about extrapolation and the mystery of the overlooked discontinuities

We report on the opinions of 49 forecasting experts on guidelines for extrapolation methods. They agreed that seasonality, trend, aggregation, and discontinuities were key features to use for selecting extrapolation methods. The strong agreement about the importance of discontinuities was surprising because this topic has been largely ignored in the forecasting literature.     

Does ownership structure matter when CPA deciding types of audit opinions

Ownership structure is one of the most important and basic corporate governance characteristics. Thus, does the ownership structure of a firm have an effect on the type of audit opinion it receives from CPA？ This paper uses a sample including 1246 non-financial listed companies from China A-share market in 2003. Empirical results show： for listed firms, external auditor＇s propensity to qualify is lower with lower proportion of public shares, or with higher concentration of shares at a marginal significant level. However, the proportions of state-owned shares and institutional shares have no significant effects on audit opinions. A possible explanation is that the ownership structure influences risk awareness and negotiation power of audit firms, influences negotiation power of clients, and then ultimately influences auditors＇ reporting decision and audit opinions. The potential policy implication is： a more dispersed ownership structure and/or a higher proportion of public shares are preferable for higher audit reporting conservatism and audit quality in China.     

Economies of scale in networks

A network's capacity can typically be increased in a variety of ways. For example, in a highway network, existing roads can be made wider or new roads added. This paper is concerned with the determination of the degree of local economies of scale in the cost function for the outputs of a congestible network when there are multiple margins for making adjustments to capacity. The main result is that under the provision of a cost-minimizing network—one for which the sum of user and capacity costs for the network's outputs is at a minimum—the degree of local economies of scale in the cost function for the network's outputs is the same along all margins for adjusting capacity. This includes what routes to establish.     

On the existence of maximum likelihood estimates in random effects models for clustered multivariate binary data

We consider a class of random effects models for clustered multivariate binary data based on the threshold crossing technique of a latent random vector. Components of this latent vector are assumed to have a Laird–Ware structure. However, in place of their Gaussian assumptions, any specified class of multivariate distribution is allowed for the random effects, and the error vector is allowed to have any strictly positive pdf. A well known member of this class of models is the multivariate probit model with random effects. We investigate sufficient and necessary conditions for the existence of maximum likelihood estimates for the location and the association parameters. Implications of our results are illustrated through some hypothetical examples.     

Welfare targeting in networks

This paper investigates welfare targeting for public goods in networks. First, we show that a tax/subsidy scheme (not necessarily budget-balanced) affects each consumer only insofar as it affects his neighbourhood. Second, we show that either a Pareto-improving income redistribution can be found or there exist Negishi weights, which we relate to the network structure. Third, in the case of Cobb–Douglas preferences, we show that a Law of Welfare Targeting holds and links two well-known notions of the comparative statics of policy interventions: neutrality and welfare paradoxical effects. Collectively, our findings uncover the importance of the $-1$ eigenvalue to economic and social policy: it is an indication of how consumers absorb the impact of income redistribution.     

Persistence in corporate networks

We examine the bipartite graphs of German corporate boards in 1993, 1999 and 2005, focusing on their projections onto directors (the “personal” network) and onto companies (the “institutional” network). The novel feature here is our focus on the temporal evolution of the two projections. The personal networks exhibit cores of highly central directors who are densely connected among themselves, while the institutional networks show a persistent core of large corporations whose identity remains mostly the same. This results in the persistent presence of a core network of very large corporations, despite substantial turnover in the identity of directors and significant changes in Germany’s corporate governance during the investigated period. Our findings strongly suggest that core persistence originates from the board appointment decisions of the very largest corporations and is largely independent of personal destinies.     

Non‐parametric regression in clustered multistate current status data with informative cluster size

Datasets examining periodontal disease records current (disease) status information of tooth‐sites, whose stochastic behavior can be attributed to a multistate system with state occupation determined at a single inspection time. In addition, the tooth‐sites remain clustered within a subject, and the number of available tooth‐sites may be representative of the true periodontal disease status of that subject, leading to an ‘informative cluster size’ scenario. To provide insulation against incorrect model assumptions, we propose a non‐parametric regression framework to estimate state occupation probabilities at a given time and state exit/entry distributions, utilizing weighted monotonic regression and smoothing techniques. We demonstrate the superior performance of our proposed weighted estimators over the unweighted counterparts via a simulation study and illustrate the methodology using a dataset on periodontal disease.