排序方式: 共有36条查询结果,搜索用时 15 毫秒
21.
This paper investigates the allocative efficiency of two non-price allocation mechanisms – the lottery (random allocation) and the waiting-line auction (queue system) – for the cases where consumers possess identical time costs (the homogeneous case), and where time costs are correlated with time valuations (the heterogeneous case). We show that the relative efficiency of the two mechanisms depends critically on a scarcity factor (measured by the ratio of the number of objects available for allocation over the number of participants) and on the shape of the distribution of valuations. We show that the lottery dominates the waiting-line auction for a wide range of situations, and that while consumer heterogeneity may improve the relative allocative efficiency of the waiting-line auction, the ranking on relative efficiency is not reversed. 相似文献
22.
Supersaturated designs (SSDs) are useful in examining many factors with a restricted number of experimental units. Many analysis methods have been proposed to analyse data from SSDs, with some methods performing better than others when data are normally distributed. It is possible that data sets violate assumptions of standard analysis methods used to analyse data from SSDs, and to date the performance of these analysis methods have not been evaluated using nonnormally distributed data sets. We conducted a simulation study with normally and nonnormally distributed data sets to compare the identification rates, power and coverage of the true models using a permutation test, the stepwise procedure and the smoothly clipped absolute deviation (SCAD) method. Results showed that at the level of significance α=0.01, the identification rates of the true models of the three methods were comparable; however at α=0.05, both the permutation test and stepwise procedures had considerably lower identification rates than SCAD. For most cases, the three methods produced high power and coverage. The experimentwise error rates (EER) were close to the nominal level (11.36%) for the stepwise method, while they were somewhat higher for the permutation test. The EER for the SCAD method were extremely high (84–87%) for the normal and t-distributions, as well as for data with outlier. 相似文献
23.
Cultural mediation through vernacularization: framing rights claims through the day‐off campaign for migrant domestic workers in Singapore 下载免费PDF全文
Chiu Yee Koh Kellynn Wee Charmian Goh Brenda S.A. Yeoh 《International migration (Geneva, Switzerland)》2017,55(3):89-104
Scholarship on civil society in Singapore has tended to emphasize the structural and institutional constraints on civil society space. Conversely, little attention is paid to the broader cultural and discursive realms in which civil society and state actors operate. This article seeks to address this gap by analysing the day‐off campaign for migrant domestic workers in Singapore. We demonstrate that by employing the cultural mediation strategy of vernacularization, civil society was able to frame migrant rights claims in a manner that resonated with the institutional logics and cultural repertoire of Singapore society. Civil society actors gained headway by adapting the discourse on migrant rights to Singapore's socio‐cultural and political context in three ways: by reframing rights claims into a moral appeal; by appealing to the cost‐benefit logics of Singaporean employers of migrant domestic workers; and by situating the provision of migrant labour protections as a relative market position. 相似文献
24.
We examine the health impacts of early access to public pension wealth by exploiting a unique policy in Singapore allowing individuals to withdraw a proportion of their pension savings after their 55th birthday. For the identification, we employ a regression discontinuity design by comparing individuals before and after their 55th birthday. To address anticipated and lagged health impacts, we adopt the donut regression discontinuity approach. Using nationally representative monthly panel data, we find that early access to pension wealth improves self-reported overall health. (JEL I10, H55, D15) 相似文献
25.
Chunhao Tu Woon Yuen Koh Shuo Jiao 《Journal of Statistical Computation and Simulation》2013,83(8):1518-1526
The generalized doubly robust estimator is proposed for estimating the average treatment effect (ATE) of multiple treatments based on the generalized propensity score (GPS). In medical researches where observational studies are conducted, estimations of ATEs are usually biased since the covariate distributions could be unbalanced among treatments. To overcome this problem, Imbens [The role of the propensity score in estimating dose-response functions, Biometrika 87 (2000), pp. 706–710] and Feng et al. [Generalized propensity score for estimating the average treatment effect of multiple treatments, Stat. Med. (2011), in press. Available at: http://onlinelibrary.wiley.com/doi/10.1002/sim.4168/abstract] proposed weighted estimators that are extensions of a ratio estimator based on GPS to estimate ATEs with multiple treatments. However, the ratio estimator always produces a larger empirical sample variance than the doubly robust estimator, which estimates an ATE between two treatments based on the estimated propensity score (PS). We conduct a simulation study to compare the performance of our proposed estimator with Imbens’ and Feng et al.’s estimators, and simulation results show that our proposed estimator outperforms their estimators in terms of bias, empirical sample variance and mean-squared error of the estimated ATEs. 相似文献
26.
Chunhao Tu Shuo Jiao Woon Yuen Koh 《Journal of Statistical Computation and Simulation》2013,83(12):2206-2218
In observational studies, unbalanced observed covariates between treatment groups often cause biased inferences on the estimation of treatment effects. Recently, generalized propensity score (GPS) has been proposed to overcome this problem; however, a practical technique to apply the GPS is lacking. This study demonstrates how clustering algorithms can be used to group similar subjects based on transformed GPS. We compare four popular clustering algorithms: k-means clustering (KMC), model-based clustering, fuzzy c-means clustering and partitioning around medoids based on the following three criteria: average dissimilarity between subjects within clusters, average Dunn index and average silhouette width under four various covariate scenarios. Simulation studies show that the KMC algorithm has overall better performance compared with the other three clustering algorithms. Therefore, we recommend using the KMC algorithm to group similar subjects based on the transformed GPS. 相似文献
27.
Committee decision making is examined in this study focusing on the role assigned to the committee members. In particular,
we are concerned about the comparison between committee performance under specialization and non-specialization of the decision
makers. Specialization (in the context of project or public policy selection) means that the decision of each committee member
is based on a narrow area, which typically results in the acquirement and use of relatively high expertise in that area. When the committee members’ expertise is already determined, specialization only means that the decision of each committee member is based solely on his/her relatively high expertise area. This form of
specialization is potentially inferior relative to non-specialization under which the decision of each committee member is
based on different areas, not just his/her relatively high expertise area. Given that the expertise of the committee members
is already determined but unknown, our analysis focuses on non-specializing individuals whose decision is based on a decision
rule that does not require information on the decision-making skills. Under these realistic assumptions, non-specialization
is shown to be preferable over specialization, depending on the aggregation rule applied by the committee. The significance
of our approach is not limited to the specific results that we obtain. Rather, it should be viewed as a first step toward
a deeper examination of the role of individual decision makers in enhancing the performance of collective decision making. 相似文献
28.
Using a Modified Social Cognitive Theory framework, this study examines the behavior modeling and lecture‐based training approaches to computer training. It extends the existing Social Cognitive Model for computer training by adding the task complexity construct to training method, prior performance, computer self‐efficacy, outcome expectations, and performance. A sample of 249 students from a large state university served as participants in a laboratory experiment that was conducted to determine the task complexity*training method and task complexity* self‐efficacy interaction effects on performance. Structural equation modeling with interaction effects was used to analyze the data. The results show that behavior modeling outperforms lecture‐based training in a measure of final performance when task complexity is high. Further, it is found that computer self‐efficacy has a greater positive effect on performance when task complexity is high than when task complexity is low. Prior performance is also found to be an important variable in the model. 相似文献
29.
Hee‐Kyung Kwon Martha A. Rueter Mi‐Sook Lee Seonju Koh Sun Wha Ok 《Journal of marriage and the family》2003,65(2):316-325
In response to the recent economic crisis in Korea and its negative effects on families, the current study examined the interrelationships among economic pressure, emotional distress, marital conflict, and marital satisfaction for 236 Korean couples. The family stress model ( Conger & Elder, 1994 ; Conger, Rueter, & Conger, 2000 ; Conger, Rueter, & Elder, 1999 ) was tested using structural equation modeling. The results generally supported the theoretical model, showing that economic pressure negatively affects marital satisfaction via emotional distress and marital conflict. The results also implied cultural differences in the process of family stress. Korean husbands' emotional distress did not affect marital conflict or marital satisfaction, suggesting that Korean husbands may differ from their wives in their reaction to emotional distress from economic pressure. 相似文献
30.
Y. B. Koh N. A. Bukhari I. Mohamed 《Journal of Statistical Computation and Simulation》2019,89(8):1394-1409
Time series of counts occur in many different contexts, the counts being usually of certain events or objects in specified time intervals. In this paper we introduce a model called parameter-driven state-space model to analyse integer-valued time series data. A key property of such model is that the distribution of the observed count data is independent, conditional on the latent process, although the observations are correlated marginally. Our simulation shows that the Monte Carlo Expectation Maximization (MCEM) algorithm and the particle method are useful for the parameter estimation of the proposed model. In the application to Malaysia dengue data, our model fits better when compared with several other models including that of Yang et al. (2015) 相似文献