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.     

Pensions reforms,workforce ageing and firm-provided welfare

This paper investigates the impact of an exogenous increase in the legal retirement age on the firms’ propensity to provide welfare services voluntarily to their employees. To this purpose we exploit a unique information derived from the Rilevazione su Imprese e Lavoro (RIL), a survey conducted in 2015 on a large and representative sample of Italian firms. Applying different regression models we show that firms which were forced to give up previously planned hirings because of the Law 201/2011 (the so-called ‘Fornero pension reform’), increased the probability of providing welfare services at workplace. By referring to the sociological, human resource management and economic literature we then argue that a sudden increase in the legal retirement age may motivate the employers to establish welfare schemes as a way to cope with an ageing workforce. Our findings also hold when propensity score matching methods are used in order to control for sample selection issues.     

The Case of the Missing Pollution Haven Hypothesis

One particularly vexing puzzle for economists and policymakers over the past several decades concerns the empirical significance of the theoretically predicted pollution haven hypothesis. While neoclassical theory and conventional wisdom both surmise that local economies will suffer deleterious effects from stricter environmental regulations, empirical studies have largely failed to validate such claims. This study utilizes the method of matching to show that the impact of stricter regulation is heterogeneous spatially, varying systematically based on location-specific attributes. Previous studies that assume a homogenous response may therefore inadvertently mask the overall impact of more stringent regulations by pooling unaffected and affected regions.JEL Classification: Q25, Q28, H00, L51, R1The authors wish to thank to Michael Crew, Anthony Heyes, an anonymous referee, Werner Antweiler, Randy Becker, Wayne Gray, Shelby Gerking, Michael Greenstone, Vern Henderson, and Arik Levinson. Participants at various university seminars and conferences also lent useful insights to this line of research.     

基于启发式算法的成品油配送计划研究

通过对成品油配送计划特点的研究与分析，建立了成品油配送计划编制的数学模型；并设计了模型求解方案；通过对实验结果的分析，证明本文设计的算法快速、有效、稳定。     

一种基于LSB的改进信息隐藏算法及实现

传统的LSB算法是将私密信息以二进制的形式嵌入到载体像素值的最低有效位,这样对图像的质量负面影响可以降到最小。本文提出了一种将过滤技术与LSB算法相结合的信息隐藏算法。利用过滤技术增强图片质量,利用LSB算法进行私密信息的嵌入。改进型的LSB算法比原算法具有更高信息存储量以及更高信息安全性等优点。     

贪心算法求解最少资源问题的探讨

面对资源的日益紧缺,如何有效合理的利用资源一直是专家学者研究和探讨的热点问题。最少资源问题是对初步资源规划问题的探讨,可以为多个资源组合规划问题的基础研究提供有效的参考作用。传统的回溯法穷举虽然能找到最少资源问题的最优解但其时间复杂度会高于o(n!),往往耗时太多,不能满足问题的及时性。提出了一种以最早开始时间为贪心策略的求解最少资源问题的贪心算法,不仅能够找到最优解,而且其时间复杂度仅为o(n2),极大提高了算法的效率。     

物流中心仓库货位优化系统的设计研究

以上海医药物流中心仓库为研究对象，为其仓库货位优化系统建立一个有效的多目标优化数学模型。并引入“类聚”的方法来解决同一产品族的货物临近放置的问题。最后，应用多目标遗传算法进行货位优化。     

大功率电子发射管的正确使用及延长其寿命的方法

大功率电子发射管广泛应用于广播电视发射设备及其他电子通信设备,文章介绍了采用冷打压老炼、灯丝电压调整、谐振匹配等技术方法延长电子管的使用寿命。     

大规模定制下基于交互式遗传算法的谈判模型研究

越来越多的企业已经认识到大规模定制是一种竞争策略,可以给企业带来竞争优势。随着大规模定制程度的提高,企业间对信息交互的及时性、有效性的要求也越来越高,企业迫切需要一种快速高效的谈判解决方案来适应大规模定制的需要。运用交互式遗传算法理论来建立谈判模型,以适应大规模定制的需要。     

A genetic algorithm based approach to transactional and QoS-aware service selection

As there are various risks of failure when Web services are deployed in unreliable environment, the execution of a composite Web service (CWS) requires the transaction mechanism to guarantee its reliable execution. However, the existing service selection approaches consider QoS and transaction separately and have not considered that transactional properties may affect the QoS such as the execution time of a CWS. This work addresses the importance of considering transactional properties and how the transactional properties affect the QoS simultaneously in the process of service selection by a QoS-aware and transactional-aware selection approach. First, a performance evaluation method is proposed to calculate the execution time of a transactional CWS. Then, a genetic algorithm based approach, which takes into account the execution time, price, transactional property and successful execution rate of CWS, is presented to achieve global optimisation service selection. Finally, experimental results show the efficiency and effectiveness of the approach.