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AbstractLiterature addressing missing data handling for random coefficient models is particularly scant, and the few studies to date have focused on the fully conditional specification framework and “reverse random coefficient” imputation. Although it has not received much attention in the literature, a joint modeling strategy that uses random within-cluster covariance matrices to preserve cluster-specific associations is a promising alternative for random coefficient analyses. This study is apparently the first to directly compare these procedures. Analytic results suggest that both imputation procedures can introduce bias-inducing incompatibilities with a random coefficient analysis model. Problems with fully conditional specification result from an incorrect distributional assumption, whereas joint imputation uses an underparameterized model that assumes uncorrelated intercepts and slopes. Monte Carlo simulations suggest that biases from these issues are tolerable if the missing data rate is 10% or lower and the sample is composed of at least 30 clusters with 15 observations per group. Furthermore, fully conditional specification tends to be superior with intraclass correlations that are typical of crosssectional data (e.g., ICC?=?.10), whereas the joint model is preferable with high values typical of longitudinal designs (e.g., ICC?=?.50). 相似文献
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Gabriele B. Durrant Rebecca Vassallo Peter W. F. Smith 《Multivariate behavioral research》2013,48(5):595-611
Multilevel multiple membership models account for situations where lower level units are nested within multiple higher level units from the same classification. Not accounting correctly for such multiple membership structures leads to biased results. The use of a multiple membership model requires selection of weights reflecting the hypothesized contribution of each level two unit and their relationship to the level one outcome. The Deviance Information Criterion (DIC) has been proposed to identify such weights. For the case of logistic regression, this study assesses, through simulation, the model identification rates of the DIC to detect the correct multiple membership weights, and the properties of model variance estimators for different weight specifications across a range of scenarios. The study is motivated by analyzing interviewer effects across waves in a longitudinal study. Interviewers can substantially influence the behavior of sample survey respondents, including their decision to participate in the survey. In the case of a longitudinal survey several interviewers may contact sample members to participate across different waves. Multilevel multiple membership models are suitable to account for the inclusion of higher-level random effects for interviewers at various waves, and to assess, for example, the relative importance of previous and current wave interviewers on current wave nonresponse. To illustrate the application, multiple membership models are applied to the UK Family and Children Survey to identify interviewer effects in a longitudinal study. The paper takes a critical view on the substantive interpretation of the model weights and provides practical guidance to statistical modelers. The main recommendation is that it is best to specify the weights in a multiple membership model by exploring different weight specifications based on the DIC, rather than prespecifying the weights. 相似文献
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Models of intertemporal choice draw on three evaluation rules, which we compare in the restricted domain of choices between smaller sooner and larger later monetary outcomes. The hyperbolic discounting model proposes an alternative‐based rule, in which options are evaluated separately. The interval discounting model proposes a hybrid rule, in which the outcomes are evaluated separately, but the delays to those outcomes are evaluated in comparison with one another. The tradeoff model proposes an attribute‐based rule, in which both outcomes and delays are evaluated in comparison with one another: People consider both the intervals between the outcomes and the compensations received or paid over those intervals. We compare highly general parametric functional forms of these models by means of a Bayesian analysis, a method of analysis not previously used in intertemporal choice. We find that the hyperbolic discounting model is outperformed by the interval discounting model, which, in turn, is outperformed by the tradeoff model. Our cognitive modeling is among the first to offer quantitative evidence against the conventional view that people make intertemporal choices by discounting the value of future outcomes, and in favor of the view that they directly compare options along the time and outcome attributes. 相似文献
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We examined how level of construal and psychological distance affected performance in a task in which value of alternatives depended on frequency of choice. Melioration, a sub‐optimal choice strategy that fails to take into account such value changes, has been found to be prevalent and difficult to change. Participants repeatedly chose between two buttons to earn as many coins as possible. Button A earned N coins, button B earned N + 3 coins, and N was the number of A presses in the last five trials. In this situation, B has a higher immediate payoff, but because choosing A increases the return from both buttons for the next five trials, maximizing A choices is the optimal strategy. We predicted that because a global perspective is needed to appreciate the dependency of value on frequency of choice, frequency of choosing the globally maximizing alternative (A) would increase when participants apply a higher level of construal and assume a more psychologically distal perspective. Study 1 manipulated construal level through segmenting the sequence of trials into segments of different size, with bigger segments representing higher level of construal. In Study 2, participants played a practice game, and we manipulated the probability of playing the actual game. Both a higher level of construal and a lower probability of playing the actual game (higher distance) increased the number of A choices. These results suggest that a broad perspective that is induced by high level of construal or by psychological distancing may reduce sub‐optimal, meliorating choice. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
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