Investor Pessimism and the German Stock Market: Exploring Google Search Queries

We analyze the relationship of retail investor sentiment and the German stock market by introducing four distinct investor pessimism indices (IPIs) based on selected aggregate Google search queries. We assess the predictive power of weekly changes in sentiment captured by the IPIs for contemporaneous and future DAX returns, volatility and trading volume. The indices are found to have individually varying, but overall remarkably high explanatory power. An increase in retail investor pessimism is accompanied by decreasing contemporaneous market returns and an increase in volatility and trading volume. Future returns tend to increase while future volatility and trading volume decrease. The outcome is in line with the conjecture of correction effects. Overall, the results are well in line with modern investor sentiment theory.     

Introducing Time‐to‐Educate in a Job‐Search Model

Transition patterns from school to work differ considerably across OECD countries. Some countries exhibit high youth unemployment rates, which can be considered an indicator of the difficulty facing young people trying to integrate into the labour market. At the same time, education is a time‐consuming process, and enrolment and dropout decisions depend on expected duration of studies as well as on job prospects with and without completed degrees. One way to model entry into the labour market is by means of job‐search models, where the job arrival hazard is a key parameter in capturing the ease or difficulty in finding a job. Standard models of job search and education assume that skills can be upgraded instantaneously (and mostly in the form of on‐the‐job training) at a fixed cost. This paper models education as a time‐consuming process, a concept which we call time‐to‐educate, during which an individual faces the trade‐off between continuing education and taking up a job.     

Drug testing and the law

This article examines judicial and administrative rulings and legislation involving or related to the issue of drug testing in the workplace. It discusses the rights of employees in the public and private sector: constitutional rights; federal, state, and local statutory rights; rights of unionized employees; and common law rights. It analyzes both the current state of the law and future directions the law may take, as courts and administrative agencies decide more cases and governmental bodies continue to pass drug testing legislation.     

等截面斜腿刚构桥的几何布局优化

以应力平方均值最小为优化目标，建立了跨越V形谷的等截面斜腿刚构桥在列车荷载和自重共同作用下的布局静力优化的数学模型，采用直接搜索法进行了设计变量的寻优。     

Physical Search

Unidirectional search is an evolutionarily stable outcome in an economy where homogenous buyers and sellers can either move or stay. It is more efficient than bidirectional search. In unidirectional search, it is more efficient if the more numerous agents move and the less numerous agents stay, than vice versa.     

Youth labor market expectations and job matching in sub-Saharan Africa: evidence from school-to-work transition surveys

In this paper, we investigate the factors that influence youth labour market expectations and outcomes. We also perform a job matching exercise to understand youth labour market dynamics in Sub-Saharan Africa. Our results show that youth education is an influential factor of youth employment expectations and employment, ceteris paribus. Higher educational attainments have a great impact on expecting and securing better jobs, particularly in the technical and professional fields. Youth with low educational attainments, particularly primary education and lower, have a higher tendency to expect to be employed in occupations with low job complexity. Our results indicate a severe job-skill mismatch in all occupational categories, both before and after the youth’s transition into the labour market. Using education as the only selection criterion, we found that less than 10 per cent of employment expectations match with skills required while 55 per cent and 34 per cent are under or over-educated for the jobs expected, respectively. Over and under education is a notable feature in youth labour markets in Sub-Saharan Africa. About 47 per cent of employed youth in the sample are overqualified for their respective jobs while 28 per cent are under qualified.     

Overeducation, regional labor markets, and spatial flexibility

For most workers, access to suitable employment is severely restricted by the fact that they look for jobs in the regional labor market rather than the global one. In this paper we analyze how macrolevel opportunities (regional market characteristics) and microlevel restrictions (the extent to which job searchers are restricted to the regional market) can help to explain the phenomenon of overeducation. We use a two-step procedure to control selective access to employment. The results show that the size of the labor market is an important factor in avoiding overeducation.     

Good News and Bad News: Search from Unknown Wage Offer Distributions

The largest market in national economies is the labor market. Labor market contracting is characterized by job search, often from unknown wage offer distributions. This paper reports experimental tests of finite horizon models of job search in which the wage offer distribution is unknown. Theoretically-optimal search from an unknown wage offer distribution can have the seemingly paradoxical property that some offers will be accepted that are lower than other offers that will be rejected in the same period of the search horizon. Thus the reservation wage property (or lowest acceptable wage path) may not exist. This can occur because an offer that is a priori relatively high (good news) can imply that it is highly probable that search is from a favorable distribution, and such an offer can look unattractive when it is an a posteriori relatively low offer from a favorable distribution (bad news). This paper reports results from experimental treatments for search from unknown distributions in which the reservation wage property does exist and treatments in which it does not exist. We find that the consistency of search behavior with search theory reported in earlier papers is robust to the presence or absence of the reservation wage property and to whether the draws come from known or unknown distributions.     

网络食品科学信息资源检索

Internet上蕴藏着丰富的食品信息资源,本文详细介绍了利用搜索引擎、各种数据库、专业网站以及学科导航系统等工具检索食品科技电子文献信息的途径和方法。     

一种改进的信息检索方法

在数据库系统的基础上，利用模糊数学的方法和工具对传统信息检索进行扩充，从而得到一种改进的信息检索方法。主要包括：提出解决问题的方法、选择实用性强的数据库系统、确定接近于自然语言的隶属函数、构造含模糊化的SQL命令并加以实现。