scholarly journals Endogeneity and Non-Response Bias in Treatment Evaluation: Nonparametric Identification of Causal Effects by Instruments

2015 ◽  
Author(s):  
Hans Fricke ◽  
Markus Frölich ◽  
Martin Huber ◽  
Michael Lechner
2017 ◽  
Vol 150 ◽  
pp. 152-154
Author(s):  
Xavier de Luna ◽  
Philip Fowler ◽  
Per Johansson

2014 ◽  
Vol 2 (2) ◽  
pp. 187-199 ◽  
Author(s):  
Xavier de Luna ◽  
Per Johansson

AbstractThe identification of average causal effects of a treatment in observational studies is typically based either on the unconfoundedness assumption (exogeneity of the treatment) or on the availability of an instrument. When available, instruments may also be used to test for the unconfoundedness assumption. In this paper, we present a set of assumptions on an instrumental variable which allows us to test for the unconfoundedness assumption, although they do not necessarily yield nonparametric identification of an average causal effect. We propose a test for the unconfoundedness assumption based on the instrumental assumptions introduced and give conditions under which the test has power. We perform a simulation study and apply the results to a case study where the interest lies in evaluating the effect of job practice on employment.


Biometrika ◽  
2019 ◽  
Vol 106 (4) ◽  
pp. 875-888
Author(s):  
S Yang ◽  
L Wang ◽  
P Ding

Summary It is important to draw causal inference from observational studies, but this becomes challenging if the confounders have missing values. Generally, causal effects are not identifiable if the confounders are missing not at random. In this article we propose a novel framework for nonparametric identification of causal effects with confounders subject to an outcome-independent missingness, which means that the missing data mechanism is independent of the outcome, given the treatment and possibly missing confounders. We then propose a nonparametric two-stage least squares estimator and a parametric estimator for causal effects.


2019 ◽  
Vol 30 (3) ◽  
pp. 157-168
Author(s):  
Helmut Hildebrandt ◽  
Jana Schill ◽  
Jana Bördgen ◽  
Andreas Kastrup ◽  
Paul Eling

Abstract. This article explores the possibility of differentiating between patients suffering from Alzheimer’s disease (AD) and patients with other kinds of dementia by focusing on false alarms (FAs) on a picture recognition task (PRT). In Study 1, we compared AD and non-AD patients on the PRT and found that FAs discriminate well between these groups. Study 2 served to improve the discriminatory power of the FA score on the picture recognition task by adding associated pairs. Here, too, the FA score differentiated well between AD and non-AD patients, though the discriminatory power did not improve. The findings suggest that AD patients show a liberal response bias. Taken together, these studies suggest that FAs in picture recognition are of major importance for the clinical diagnosis of AD.


Author(s):  
Alicia A. Stachowski ◽  
John T. Kulas

Abstract. The current paper explores whether self and observer reports of personality are properly viewed through a contrasting lens (as opposed to a more consonant framework). Specifically, we challenge the assumption that self-reports are more susceptible to certain forms of response bias than are informant reports. We do so by examining whether selves and observers are similarly or differently drawn to socially desirable and/or normative influences in personality assessment. Targets rated their own personalities and recommended another person to also do so along shared sets of items diversely contaminated with socially desirable content. The recommended informant then invited a third individual to additionally make ratings of the original target. Profile correlations, analysis of variances (ANOVAs), and simple patterns of agreement/disagreement consistently converged on a strong normative effect paralleling item desirability, with all three rater types exhibiting a tendency to reject socially undesirable descriptors while also endorsing desirable indicators. These tendencies were, in fact, more prominent for informants than they were for self-raters. In their entirety, our results provide a note of caution regarding the strategy of using non-self informants as a comforting comparative benchmark within psychological measurement applications.


2013 ◽  
Vol 29 (4) ◽  
pp. 253-262 ◽  
Author(s):  
Omer Hegedish ◽  
Dan Hoofien

The Word Memory Test (WMT) is one of the most sensitive forced-choice tests available designed to evaluate negative response bias (NRB). Presently there is no valid verbal test designed to evaluate NRB for Hebrew-speaking patients. The aims of the present study were to validate the response bias measures of the WMT among Hebrew-speaking patients with acquired brain injuries and to reveal the malingering base rate among Israeli patients involved in compensation-seeking. Participants were 112 patients. The Test of Memory Malingering (TOMM) was used for convergent validity and injury related variables were used for concurrent validity. A translated version of the WMT had high split-half reliability. Regarding convergent validity, WMT effort measures had high positive correlations with the TOMM. Moreover, based on TOMM cutoff scores for classification, the WMT had reasonable classification rates. Regarding concurrent validity, multivariate logistic regression revealed that failure in the WMT was significantly predicted by normal brainscans and involvement in compensation-seeking behavior. The baserate of probable malingering was 34%. These findings emphasize the universality of the WMT in detecting NRB and establishing a malingered neurocognitive dysfunction baserate among Israeli patients involved in compensation-seeking.


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