旅行社产品同质化及其成因分析

本文主要讨论了旅行社产品同质化的表现、影响和成因,特别强调了旅行社产品在质量方面的低水平同质化问题,并从直接和间接两个方面对旅行社产品同质化成因做了分析。     

The sample estimation

Statistical research, as a rule, is based on the sample. Therefore, it is important to evaluate the quality of the sample studied. Our sample evaluation is based on a new interpretation of such concepts as a random factor, disturbance factor, homogeneity, representativeness, and population.     

Chi-square Distribution as a Research Tool,and Some of Its Most Important Parametric and Non-parametric Applications

When researchers are testing the validity of claims during their research, they may use either parametric methods （if they exist） or non-parametric methods if appropriate parametric methods do not exist. The Chi-square （x2） distribution plays an important role in both parametric and non-parametric methods and many of its most important applications are explored in this paper. This paper provides an excellent summation of the properties and capabilities of the very versatile x2 distribution, and many specific applications and suggestions for additional future applications.     

高校学报的差异化定位策略

高校学报同质化严重,已导致高校学报缺乏学科特色,对一流学术论文和创新性研究成果缺乏吸引力,严重影响了高校学报的质量与水平。高校学报应结合市场需求和学校学科优势,实施差异化定位,使之在读者心目中占据有差别、有意义的地位。     

Understanding Price Variation Across Stores and Supermarket Chains: Some Implications for CPI Aggregation Methods

The empirical literature on price indices consistently finds that aggregation methods have a considerable impact, particularly when scanner data are used. This paper outlines a novel approach to test for the homogeneity of goods and hence for the appropriateness of aggregation. A hedonic regression framework is used to test for item homogeneity across four supermarket chains and across stores within each of these supermarket chains. We find empirical support for the aggregation of prices across stores which belong to the same supermarket chain. Support was also found for the aggregation of prices across three of the four supermarket chains.     

国产烯烃聚合催化剂载体——二氧化硅的工业应用

论述了国产硅胶的两次工业化应用过程,并提供相关分析数据,通过对相应的数据比较,得出结论,国产硅胶在活化时的流动性和最终的聚乙烯产品粉末筛分的均匀性上要好于进口硅胶,因此,国产硅胶完全可以替代进口硅胶。     

Testing Heterogeneous Image in Cultural/Non‐cultural Tourism Markets: a Latent Model Approach

We identify the latent variable ‘destination image’ to segment tourism demand based on the different types of behaviour generated by those images. We used simultaneous latent structure analysis, which also permits a comparison of the degree of homogeneity or heterogeneity of two or more tourist markets. After presenting the most significant methodological aspects of this technique, we describe its application to the data of a study of the behaviour of tourism demand of Andalusia to determine whether those tourists with a marked inclination for cultural tourism have a similar (homogeneous) image of this destination as do other tourists. Copyright © 2011 John Wiley & Sons, Ltd.     

Stochastic interest rate modelling using a single or multiple curves: an empirical performance analysis of the Lévy forward price model

In current financial markets negative interest rates have become rather persistent, while in theory it is often common practice to discard such rates as incredible and irrelevant. However, from a risk management perspective, it is crucially important to financial institutions to properly account for this phenomenon in their Asset Liability Management (ALM) studies. In this paper, we develop a coherent framework on how to best incorporate negative interest rates in these studies through a single curve stochastic term structure model and compare it to its multiple curve analogue. It turns out that, from the wide range of available single curve models, especially the Lévy Forward Price model (LFPM) of Eberlein and Özkan [The Lévy LIBOR model. Financ. Stoch., 2005, 9, 327–348] seems appropriate for ALM purposes. This paper describes an optimisation routine for calibrating this LFPM under the risk-neutral measure in both the single and multiple curve framework to the market prices of interest rate caplets with different strike rates, maturities and tenors. In addition, an empirical performance analysis is made of the single and multiple curve LFPM, where we include four deterministic volatility specifications and provide an explicit parametrisation of a piecewise homogeneity restriction with both deterministic and random breakpoints. This comparative analysis indicates that both the single and multiple curve LFPM is best adopted with the Linear-Exponential Volatility (LEV) specification and that deterministic breakpoints should be included, rather than random breakpoints.     

The effect of industry classification on analyst following and the properties of their earnings forecasts

Using a comprehensive data set, we compare four broadly available industry classification schemes (Standard Industrial Classification (SIC), North American Industry Classification System (NAICS), Fama–French classification (FF) and Global Industry Classification Standard (GICS)) in their effectiveness to group analysts and their earnings forecast properties. We demonstrate the advantage of the GICS to be consistent across different forecasting properties and across different groups of firms. Our results suggest that GICS should be utilized in research designs, either in the primary analysis or as a necessary corroboration.     

Exploratory Analysis of Similarities Between Social Choice Rules

Nurmi (1987) investigated the relationship between voting rules by determining the frequency that two rules pick the same winner. We use statistical techniques such as hierarchical clustering and multidimensional scaling to further understand the relationships between rules. We use the urn model with a parameter representing contagion to model the presence of social homogeneity within the group of agents and investigate how the classification tree of the rules changes when the homogeneity of the voting population is increased. We discovered that the topology of the classification tree changes quite substantially when the parameter of homogeneity is increased from 0 to 1. We describe the most interesting changes and explain some of them. Most common social choice rules are included, 26 in total. Jel Classification: D7