Google data in bridge equation models for German GDP

Interest in the use of “big data” when it comes to forecasting macroeconomic time series such as private consumption or unemployment has increased; however, applications to the forecasting of GDP remain rather rare. This paper incorporates Google search data into a bridge equation model, a version of which usually belongs to the suite of forecasting models at central banks. We show how such big data information can be integrated, with an emphasis on the appeal of the underlying model in this respect. As the decision as to which Google search terms should be added to which equation is crucial —- both for the forecasting performance itself and for the economic consistency of the implied relationships —- we compare different (ad-hoc, factor and shrinkage) approaches in terms of their pseudo real time out-of-sample forecast performances for GDP, various GDP components and monthly activity indicators. We find that sizeable gains can indeed be obtained by using Google search data, where the best-performing Google variable selection approach varies according to the target variable. Thus, assigning the selection methods flexibly to the targets leads to the most robust outcomes overall in all layers of the system.     

Local Times of Bernoulli Walk

The joint probability generating functions of local times of Bernoulli walk at various stopping times are determined by simple functional equations. The results can be interpreted by means of branching processes with immigration satisfying the same equations. One way of working with these results is to specialize and evaluate the derived equations, but a more elegant and efficient way is to compare these equations with corresponding functional equations for branching processes.     

Nonlinear Structural Equation Models with the Theory of Planned Behavior: Comparison of Multiple Group and Latent Product Term Analyses

Nonlinear relationships in structural equation analysis became moreinteresting for applied researchers since the implementation of nonlinearconstraints in software programs (i.e., LISREL). This article provides acomprehensive application of the expectancy × value part of the Theory of Planned Behavior (Ajzen, 1991) including interactions of latent variables.The main purpose of the study is to overcome limitations of similarprevious analyses of Baumgartner and Bagozzi (1995) and Yang Jonsson (1997,1998) with an empirical example from representative survey data. Nonlinearrelationships of the theories' constructs (Attitude toward the behavior, subjectivenorm and perceived behavioral control) are analyzed one upon another withmultiple group comparisons and latent interaction models. Results confirmthe strategy to use multiple group techniques for preliminary analyses(i.e., detection of an interaction effect). With latent interaction models thestrength and the significance of the interaction is estimated under controlfor random measurement error. Parameters, standard errors, andgoodness-of-fit statistics are compared between three estimationtechniques (ML, GLS and WLS). Multiple group analyses and latentinteraction modeling detect a significant interaction for perceivedbehavioral control but not for attitude toward the behavior and subjective norm. Variations of the estimators of the perceived behavioral controlsubmodel is proved by bootstrapping. Further model improvements andalternative model techniques are discussed in the final chapter.     

利用微分方程求辅助函数证明中值定理

对于微分中值定理有关证明,"奇妙"的构造辅助函数问题。利用微分方程的求解,分析辅助函数的内在特征,给出一种构造方法。     

The nature and units of social selection

On the basis of the technical definition of selection developed by George Price (1995), we describe two forms of selection that commonly occur at the social level, subset selection and generative selection. Both forms of selection are abstract and general, and therefore also incomplete; both leave aside the question of explaining the selection criterion and why entities possess stable traits. However, an important difference between the two kinds of selection is that generative selection can accommodate an explanation of how new variation is created, while subset selection cannot. An evolutionary process involving repeated cycles of generative selection can, in principle, continue indefinitely because imperfect replication generates new variation along the way, whereas subset selection reduces variation and eventually grinds to a halt. Even if the two kinds of selection are very different, they share a number of features. First, neither subset selection nor generative selection implies improvement: neither kind of selection necessarily leads to efficiency or implies systematic outcomes. Second, both subset selection and generative selection can lead to extremely rapid effects in a social population. Third, in the social domain, both generative selection and subset selection involve choice and preference in some way: neither form of selection necessarily excludes intentionality. In concluding the article, we single out a challenge for future research in identifying the role of various units of culture in selection processes and the multiple levels at which social selection processes take place.     

垄断厂商与中间商的分销价格博弈

完全信息条件下,在各自领域处于垄断地位的厂商和中间商就分销价格和促销费用博弈时会达到多个纳什均衡,即"高分销价格,低促销费用"或"低分销价格,高促销费用"。若从分销价格和促销费用服从连续分布的基础上进行分析,博弈双方会取得惟一的纳什均衡解。这一结果尽管是在假设条件下的静态均衡,但却同受到各种条件制约的现实博弈结果相类似。     

The shadow economy in three Mediterranean countries: France,Spain and Greece. A MIMIC approach

This paper offers estimations of the evolution of the shadow economy in three Mediterranean countries, namely France, Spain and Greece. A multiple indicators and multiple causes model based on the latent variable structural theory has been applied. As established by Giles (Working paper on monitoring the health of the tax system, 1995), filtered data to solve the non-stationary problems are used. The model includes the tax burden (both as a whole and disaggregated into direct taxes, indirect taxes and social security contributions), a proxy of regulation burden, theu nemployment rate and self-employment as causes of the shadow economy and the GDP growth rate, the labour force participation ratio and the currency ratio as indicators of the underground economy. The results confirm that unemployment, the fiscal burden and self-employment are the main causes of the shadow economy in these countries, and confirm that an inverse relationship exists between the official GDP growth rate and that of the unofficial economy. This paper has benefited from the comments and suggestions of the anonymous referees. The usual disclaimer applies. The paper was partly written when third author was visiting Real Colegio Complutense at Harvard University. The hospitality of this Institution is gratefully acknowledged.     

Measuring entrepreneurial quality in southern Europe

The main objective of this paper is working out an empirical methodology to measure the quality of the entrepreneur’s booster function, so that policy makers have an appropriate diagnosis of the qualities of entrepreneurs in their area. In this sense, two essential elements are the construction of an explanatory model, and the establishment of an entrepreneurial typology with respect to quality levels. This methodology is then applied to determine the quality level of entrepreneurs in Seville province (southern Spain), using Partial Least Squares estimation technique on a survey of 278 entrepreneurs from various activity sectors and with firms of different sizes.     

Bargaining regimes and wages in Portugal

In this paper we analyse the bargaining regime wage-effect in Portugal. The results indicate that the bargaining regime coverage is important in explaining the variability of wages. Wage differentials between bargaining regimes are substantial, a fact which may be related to a decentralised wage setting which prevails in Portugal. The highest wages are generated by multi-firm negotiations and the lowest are generated by sectoral contracts. Single-firm contracts align at an intermediate level in the ranking.Received: April 2001, Accepted: May 2002, JEL Classification: J31Correspondence to: Pedro T. PereiraWe are very grateful to an anonymous referee. Financial support from program PRAXIS XXI under grant PRAXIS/2/2.1/CSH/781/95 and FEDER is acknowledged. The third author also acknowledges financial support from program PRAXIS XXI under grant BD/3486/94 and from the University of the Azores.     

一类三阶差分方程的周期轨及其稳定性和吸引性

通过变量代换得到三阶差分方程 xn＋1=xnxn-1＋α/xn＋xn-2,α〉0,x-2,x-1,x0〉0,n=0,1,2,… 的等价形式,把该三阶差分方程等价地化为一个三维一阶差分方程,并定义此三维一阶差分方程为映射T,通过映射T的局部线性化研究了该三阶差分方程的1周期和2周期轨道的存在性、稳定性及其吸引性.