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作者:Ben-Michael, Eli; Feller, Avi; Rothstein, Jesse
作者单位:Harvard University; University of California System; University of California Berkeley; University of California System; University of California Berkeley
摘要:The synthetic control method (SCM) is a popular approach for estimating the impact of a treatment on a single unit in panel data settings. The synthetic control is a weighted average of control units that balances the treated unit's pretreatment outcomes and other covariates as closely as possible. A critical feature of the original proposal is to use SCM only when the fit on pretreatment outcomes is excellent. We propose Augmented SCM as an extension of SCM to settings where such pretreatment...
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作者:Ruggeri, Fabrizio
作者单位:Consiglio Nazionale delle Ricerche (CNR); Istituto di Matematica Applicata e Tecnologie Informatiche Enrico Magenes (IMATI-CNR)
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作者:Moura, Ricardo; Klein, Martin; Zylstra, John; Coelho, Carlos A.; Sinha, Bimal
作者单位:Universidade Nova de Lisboa; US Food & Drug Administration (FDA); University System of Maryland; University of Maryland Baltimore County; Universidade Nova de Lisboa
摘要:In this article, the authors derive the likelihood-based exact inference for singly and multiply imputed synthetic data in the context of a multivariate regression model. The synthetic data are generated via the Plug-in Sampling method, where the unknown parameters in the model are set equal to the observed values of their point estimators based on the original data, and synthetic data are drawn from this estimated version of the model. Simulation studies are carried out in order to confirm th...
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作者:Lee, Kwonsang; Small, Dylan S.; Dominici, Francesca
作者单位:Sungkyunkwan University (SKKU); University of Pennsylvania; Harvard University; Harvard T.H. Chan School of Public Health
摘要:Several studies have provided strong evidence that long-term exposure to air pollution, even at low levels, increases risk of mortality. As regulatory actions are becoming prohibitively expensive, robust evidence to guide the development of targeted interventions to protect the most vulnerable is needed. In this article, we introduce a novel statistical method that (i) discovers subgroups whose effects substantially differ from the population mean, and (ii) uses randomization-based tests to as...
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作者:Li, Huazhang; Wang, Yaotian; Yan, Guofen; Sun, Yinge; Tanabe, Seiji; Liu, Chang-Chia; Quigg, Mark S.; Zhang, Tingting
作者单位:University of Virginia; Pennsylvania Commonwealth System of Higher Education (PCSHE); University of Pittsburgh; University of Virginia; University of Virginia; University of Virginia; University of Virginia
摘要:The human brain is a directional network system of brain regions involving directional connectivity. Seizures are a directional network phenomenon as abnormal neuronal activities start from a seizure onset zone (SOZ) and propagate to otherwise healthy regions. To localize the SOZ of an epileptic patient, clinicians use intracranial electroencephalography (iEEG) to record the patient's intracranial brain activity in many small regions. iEEG data are high-dimensional multivariate time series. We...
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作者:Liu, Lin; Shahn, Zach; Robins, James M.; Rotnitzky, Andrea
作者单位:Shanghai Jiao Tong University; Shanghai Jiao Tong University; International Business Machines (IBM); IBM USA; Harvard University; Universidad Torcuato Di Tella; Consejo Nacional de Investigaciones Cientificas y Tecnicas (CONICET)
摘要:We derive new estimators of an optimal joint testing and treatment regime under the no direct effect (NDE) assumption that a given laboratory, diagnostic, or screening test has no effect on a patient's clinical outcomes except through the effect of the test results on the choice of treatment. We model the optimal joint strategy with an optimal structural nested mean model (opt-SNMM). The proposed estimators are more efficient than previous estimators of the parameters of an opt-SNMM because th...
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作者:Cattaneo, Matias D.; Keele, Luke; Titiunik, Rocio; Vazquez-Bare, Gonzalo
作者单位:Princeton University; University of Pennsylvania; Princeton University; University of California System; University of California Santa Barbara
摘要:In nonexperimental settings, the regression discontinuity (RD) design is one of the most credible identification strategies for program evaluation and causal inference. However, RD treatment effect estimands are necessarily local, making statistical methods for the extrapolation of these effects a key area for development. We introduce a new method for extrapolation of RD effects that relies on the presence of multiple cutoffs, and is therefore design-based. Our approach employs an easy-to-int...
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作者:Wu, Jason; Ding, Peng
作者单位:University of California System; University of California Berkeley
摘要:The Fisher randomization test (FRT) is appropriate for any test statistic, under a sharp null hypothesis that can recover all missing potential outcomes. However, it is often sought after to test a weak null hypothesis that the treatment does not affect the units on average. To use the FRT for a weak null hypothesis, we must address two issues. First, we need to impute the missing potential outcomes although the weak null hypothesis cannot determine all of them. Second, we need to choose a pro...
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作者:Bai, Jushan; Ng, Serena
作者单位:Columbia University; National Bureau of Economic Research
摘要:This article proposes an imputation procedure that uses the factors estimated from a tall block along with the re-rotated loadings estimated from a wide block to impute missing values in a panel of data. Assuming that a strong factor structure holds for the full panel of data and its sub-blocks, it is shown that the common component can be consistently estimated at four different rates of convergence without requiring regularization or iteration. An asymptotic analysis of the estimation error ...
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作者:Khan, Md Kamrul Hasan; Chakraborty, Avishek; Petris, Giovanni; Wilson, Barry T.
作者单位:University of Arkansas System; University of Arkansas Fayetteville; United States Department of Agriculture (USDA); United States Forest Service
摘要:The USDA Forest Service uses satellite imagery, along with a sample of national forest inventory field plots, to monitor and predict changes in forest conditions over time throughout the United States. We specifically focus on a 230,400 ha region in north-central Wisconsin between 2003 and 2012. The auxiliary data from the satellite imagery of this region are relatively dense in space and time, and can be used to learn how forest conditions changed over that decade. However, these records have...