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81.
This study identifies three groups of job seekers in terms of the channels used to search for jobs: the formal channel involving only official procedures to obtain a job, the informal channel using only social contacts to obtain a job, and the joint channel leveraging both social contacts and official procedures. The analysis of a national sample survey of China shows that joint channel users, due to their relatively higher level of social capital, not only make more job search attempts but also obtain higher income than formal channel users. Meanwhile, joint channel users, because of their relative advantages in both human capital and social capital, not only make more job attempts but also obtain higher income than informal channel users. The two comparisons offer a new strategy to test the causal role social capital plays in labour market success, regardless of whether social capital is exogenous or endogenous to human capital. 相似文献
82.
Tyler J. VanderWeele James M. Robins 《Journal of the Royal Statistical Society. Series B, Statistical methodology》2010,72(1):111-127
Summary. Formal rules governing signed edges on causal directed acyclic graphs are described and it is shown how these rules can be useful in reasoning about causality. Specifically, the notions of a monotonic effect, a weak monotonic effect and a signed edge are introduced. Results are developed relating these monotonic effects and signed edges to the sign of the causal effect of an intervention in the presence of intermediate variables. The incorporation of signed edges in the directed acyclic graph causal framework furthermore allows for the development of rules governing the relationship between monotonic effects and the sign of the covariance between two variables. It is shown that when certain assumptions about monotonic effects can be made then these results can be used to draw conclusions about the presence of causal effects even when data are missing on confounding variables. 相似文献
83.
Social integration is considered crucially important for understanding the adverse effect of unemployment on mental health. Social integration is assumed to either bring about the health effects of unemployment (causal pathway hypothesis) or shield the unemployed from such effects (buffering hypothesis). However, there is scarce empirical evidence, especially based on panel data, regarding these two hypotheses. In our analysis, we use up to ten waves of the “Labour Market and Social Security” (PASS) German panel study and apply fixed effects panel regressions to account for unobserved confounders. We test several indicators that cover different aspects of social integration (numbers of strong and weak ties, conflict in the household, employed friends, general and job search-specific social support). We find no empirical support for the causal pathway hypothesis and only very limited support for the buffering hypothesis. 相似文献
84.
《Risk analysis》2018,38(5):947-961
Many studies have investigated public reactions to nuclear accidents. However, few studies focused on more common events when a serious accident could have happened but did not. This study evaluated public response (emotional, cognitive, and behavioral) over three phases of a near‐miss nuclear accident. Simulating a loss‐of‐coolant accident (LOCA) scenario, we manipulated (1) attribution for the initial cause of the incident (software failure vs. cyber terrorist attack vs. earthquake), (2) attribution for halting the incident (fail‐safe system design vs. an intervention by an individual expert vs. a chance coincidence), and (3) level of uncertainty (certain vs. uncertain) about risk of a future radiation leak after the LOCA is halted. A total of 773 respondents were sampled using a 3 × 3 × 2 between‐subjects design. Results from both MANCOVA and structural equation modeling (SEM) indicate that respondents experienced more negative affect, perceived more risk, and expressed more avoidance behavioral intention when the near‐miss event was initiated by an external attributed source (e.g., earthquake) compared to an internally attributed source (e.g., software failure). Similarly, respondents also indicated greater negative affect, perceived risk, and avoidance behavioral intentions when the future impact of the near‐miss incident on people and the environment remained uncertain. Results from SEM analyses also suggested that negative affect predicted risk perception, and both predicted avoidance behavior. Affect, risk perception, and avoidance behavior demonstrated high stability (i.e., reliability) from one phase to the next. 相似文献
85.
This paper reports a study, involving a network drawing approach, that examined how nurses perceive the interrelationship between causes of workplace stress. Network analysis originated in sociology as a method of examining the relationship between people, objects or events. It has recently been adapted to examine participants' perceptions of the relationships between causes of a phenomenon, either by asking participants to complete a grid rating the strength of all the possible links between causes or by getting them to draw a diagram of the links that they think are important. The network drawing technique, in which participants are asked to draw a diagram indicating perceived causal links between nominated causes of stress and also to indicate the strength of these links, was employed in this study. The causes of stress were taken from a previous study in which nurses kept a diary for one week detailing stressful events and their causes. There were 48 participants in the present study and the main results confirmed the importance of staffing levels and inadequate support as perceived direct causes of stress. The study also revealed the importance of indirect links between staffing levels and other causes of stress. The networks illustrate how direct and mediating causes of stress are connected and lie largely outside nurses' control. The results are discussed in relation to other recent work on the causes and experience of stress by nursing staff. 相似文献
86.
Opportunism in Capital Budget Recommendations: The Effects of Past Performance and Its Attributions*
This study uses an experiment to examine the separate and combined effects of managers' loss aversion and their causal attributions about their divisions' performance on tendencies to make goal‐incongruent capital budget recommendations. We find that managers' recommendations are biased by their loss aversion. In particular, managers of high‐performing divisions are more likely than managers of low‐performing divisions to propose investments that maximize their division's short‐term profits at the expense of the firm's long‐term value. We also find that managers' recommendations are biased by their causal attributions. In particular, managers are more likely to propose investments that maximize their division's short‐term profits at the expense of the firm's long‐term value when they attribute their division's performance to external causes (e.g., task difficulty or luck) rather than to internal causes (e.g., managerial ability or effort). Further, the effects of causal attributions are greater for managers of high‐performing divisions than for managers of low‐performing divisions. The study's findings are important because loss aversion and causal attributions are often manifested in firms. Thus, they may bias managers' decisions, which in turn may be detrimental to the firms' long‐term value. 相似文献
87.
The process of translating objectives into actions is a difficult task. This difficulty is due to the wide range of possibilities and the lack of structured information. Managers must take into account relevant information and generate a range of options before a decision is reached. So far, little is available to guide managers in translating a set of objectives into actions. This paper presents a three‐stage action‐planning process to address this gap. The process, supported by a software tool, takes managers through the stages of model building, action generation, and action evaluation and selection. A case study illustrates the application of the process. The paper concludes by discussing the implication of this work for managers and academics. 相似文献
88.
S. A. Murphy 《Journal of the Royal Statistical Society. Series B, Statistical methodology》2003,65(2):331-355
Summary. A dynamic treatment regime is a list of decision rules, one per time interval, for how the level of treatment will be tailored through time to an individual's changing status. The goal of this paper is to use experimental or observational data to estimate decision regimes that result in a maximal mean response. To explicate our objective and to state the assumptions, we use the potential outcomes model. The method proposed makes smooth parametric assumptions only on quantities that are directly relevant to the goal of estimating the optimal rules. We illustrate the methodology proposed via a small simulation. 相似文献
89.
倾向性得分是估计平均处理效应的重要工具。但在观察性研究中,通常会由于协变量在处理组与对照组分布的不平衡性而导致极端倾向性得分的出现,即存在十分接近于0或1的倾向性得分,这使得因果推断的强可忽略假设接近于违背,进而导致平均处理效应的估计出现较大的偏差与方差。Li等(2018a)提出了协变量平衡加权法,在无混杂性假设下通过实现协变量分布的加权平衡,解决了极端倾向性得分带来的影响。本文在此基础上,提出了基于协变量平衡加权法的稳健且有效的估计方法,并通过引入超级学习算法提升了模型在实证应用中的稳健性;更进一步,将前一方法推广至理论上不依赖于结果回归模型和倾向性得分模型假设的基于协变量平衡加权的稳健有效估计。蒙特卡洛模拟表明,本文提出的两种方法在结果回归模型和倾向性得分模型均存在误设时仍具有极小的偏差和方差。实证部分将两种方法应用于右心导管插入术数据,发现右心导管插入术大约会增加患者6. 3%死亡率。 相似文献
90.
生育政策与出生性别比偏高 总被引:2,自引:0,他引:2
李建新 《中国农业大学学报(社会科学版)》2008,25(3):68-76
自20世纪80年代以来,中国人口出生性别比开始偏离正常值且持续偏高,一般认为,这是多种影响因素共同作用的结果。在诸多影响因素中,何者为主要因素却有很大的分歧。笔者认为,虽然影响我国出生人口性别比升高的原因是复杂的、多因素的,但是,20世纪80年代以来实施的严格的计划生育政策不仅与出生性别比偏高直接相关,而且是诸多影响因素中最主要的,偏严的生育政策是中国出生性别比长期严重失衡的主要原因。 相似文献