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941.
ABSTRACT . “Bargaining with the Devil: Commentary on the Ostroms’‘Quest for Meaning in Public Choice’” provides a commentary on Elinor Ostrom and Vincent Ostrom's paper, “The Quest for Meaning in Public Choice.” This discussion focuses on the challenging tension that exists between social scientific knowledge and social practices. It suggests that historical agents may have solved the dilemma of cooperation prior to rational choice theorists’ invention of the public goods problem.  相似文献   
942.
Robustness issues in multilevel regression analysis   总被引:8,自引:0,他引:8  
A multilevel problem concerns a population with a hierarchical structure. A sample from such a population can be described as a multistage sample. First, a sample of higher level units is drawn (e.g. schools or organizations), and next a sample of the sub‐units from the available units (e.g. pupils in schools or employees in organizations). In such samples, the individual observations are in general not completely independent. Multilevel analysis software accounts for this dependence and in recent years these programs have been widely accepted. Two problems that occur in the practice of multilevel modeling will be discussed. The first problem is the choice of the sample sizes at the different levels. What are sufficient sample sizes for accurate estimation? The second problem is the normality assumption of the level‐2 error distribution. When one wants to conduct tests of significance, the errors need to be normally distributed. What happens when this is not the case? In this paper, simulation studies are used to answer both questions. With respect to the first question, the results show that a small sample size at level two (meaning a sample of 50 or less) leads to biased estimates of the second‐level standard errors. The answer to the second question is that only the standard errors for the random effects at the second level are highly inaccurate if the distributional assumptions concerning the level‐2 errors are not fulfilled. Robust standard errors turn out to be more reliable than the asymptotic standard errors based on maximum likelihood.  相似文献   
943.
The goal of meta-analysis is to integrate the research results of a number of studies on a specific topic. Characteristic for meta-analysis is that in general only the summary statistics of the studies are used and not the original data. When the published research results to be integrated are longitudinal, multilevel analysis can be used for the meta-analysis. We will demonstrate this with an example of longitudinal data on the mental development of infants. We distinguish four levels in the data. The highest level (4) is the publication, in which the results of one or more studies are published. The third level consists of the separate studies. At this level we have knowledge about the degree of prematurity of the group of infants in the specific study. The second level are the repeated measures. We have data about the test age, the mental development, the corresponding standard deviations, and the sample sizes. The lowest level is needed for the specification of the meta-analysis model. Both the way in which the multilevel model has to be specified (the Mln-program is used) as the results will be presented and interpreted.  相似文献   
944.
For a multilevel model with two levels and only a random intercept, the quality of different estimators of the random intercept is examined. Analytical results are given for the marginal model interpretation where negative estimates of the variance components are allowed for. Except for four or five level-2 units, the Empirical Bayes Estimator (EBE) has a lower average Bayes risk than the Ordinary Least Squares Estimator (OLSE). The EBEs based on restricted maximum likelihood (REML) estimators of the variance components have a lower Bayes risk than the EBEs based on maximum likelihood (ML) estimators. For the hierarchical model interpretation, where estimates of the variance components are restricted being positive, Monte Carlo simulations were done. In this case the EBE has a lower average Bayes risk than the OLSE, also for four or five level-2 units. For large numbers of level-1 (30) or level-2 units (100), the performances of REML-based and ML-based EBEs are comparable. For small numbers of level-1 (10) and level-2 units (25), the REML-based EBEs have a lower Bayes risk than ML-based EBEs only for high intraclass correlations (0.5).  相似文献   
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946.
Given the decision to create a second class of stock through a dual-class structure, we propose that management is more (less) likely to create a liquid secondary market for both classes of shares the lower (higher) its willingness to tie its personal wealth to firm performance. If market makers recognize this relation, they should assign a higher likelihood to trades motivated by superior information in shares of firms that list both classes of stock and a lower likelihood for firms that list only one class of stock pursuant to recapitalization. Additionally, they should assign a lower likelihood to trades motivated by superior information in shares of IPOs that choose a dual-class structure and list only one class relative to IPOs that remain single-class. Our empirical tests based on IPOS and recaps between 1985 and 1988 provide support for these propositions.  相似文献   
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949.
The distribution of shocks to GDP growth rates is found to be exponential rather than normal. Their standard deviation scales with GDPβ where β=−0.15±0.03. These macroeconomic results place restrictions on the microeconomic structure of interactions between agents.  相似文献   
950.
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