scholarly journals Bayesian Two-Stage Robust Causal Modeling with Instrumental Variables using Student's t Distributions

2017 ◽  
Author(s):  
Dingjing Shi ◽  
Xin Tong
Keyword(s):  
Instrumental Variables ◽  
Causal Modeling ◽  
Two Stage ◽  
Student’S T

Mitigating Selection Bias: A Bayesian Approach to Two-stage Causal Modeling With Instrumental Variables for Nonnormal Missing Data

2020 ◽  
pp. 004912412091492
Author(s):  
Dingjing Shi ◽  
Xin Tong
Keyword(s):  
Missing Data ◽  
Selection Bias ◽  
Instrumental Variables ◽  
Bayesian Approach ◽  
Real Data ◽  
Average Treatment Effect ◽  
Causal Modeling ◽  
Continuous Treatment ◽  
Nonnormal Data ◽  
Two Stage

This study proposes a two-stage causal modeling with instrumental variables to mitigate selection bias, provide correct standard error estimates, and address nonnormal and missing data issues simultaneously. Bayesian methods are used for model estimation. Robust methods with Student’s t distributions are used to account for nonnormal data. Ignorable missing data are handled by multiple imputation techniques, while nonignorable missing data are handled by an added-on selection model structure. In addition to categorical treatment data, this study extends the work to continuous treatment variables. Monte Carlo simulation studies are conducted showing that the proposed Bayesian approach can well address common issues in existing methods. We provide a real data example on the early childhood relative age effect study to illustrate the application of the proposed method. The proposed method can be easily implemented using the R software package "ALMOND" (Analysis of Local Average Treatment Effect for missing or/and Nonnormal Data).

An introduction to model implied instrumental variables using two stage least squares (MIIV-2SLS) in structural equation models (SEMs).

2021 ◽  
Author(s):  
Kenneth A. Bollen ◽  
Zachary F. Fisher ◽  
Michael L. Giordano ◽  
Adam G. Lilly ◽  
Lan Luo ◽  
...  
Keyword(s):  
Least Squares ◽  
Instrumental Variables ◽  
Structural Equation ◽  
Structural Equation Models ◽  
Two Stage ◽  
Two Stage Least Squares

Identification of Physical Parameters and Instrumental Variables Validation With Two-Stage Least Squares Estimator

2013 ◽  
Vol 21 (4) ◽  
pp. 1386-1393 ◽  
Author(s):  
Alexandre Janot ◽  
Pierre-Olivier Vandanjon ◽  
Maxime Gautier
Keyword(s):  
Least Squares ◽  
Instrumental Variables ◽  
Least Squares Estimator ◽  
Physical Parameters ◽  
Two Stage ◽  
Two Stage Least Squares

scholarly journals The Causal Interpretation of Two-Stage Least Squares with Multiple Instrumental Variables

2019 ◽  
Author(s):  
Magne Mogstad ◽  
Alexander Torgovitsky ◽  
Christopher Walters
Keyword(s):  
Least Squares ◽  
Instrumental Variables ◽  
Causal Interpretation ◽  
Two Stage ◽  
Two Stage Least Squares

scholarly journals ASYMPTOTIC DISTRIBUTION OF JIVE IN A HETEROSKEDASTIC IV REGRESSION WITH MANY INSTRUMENTS

2011 ◽  
Vol 28 (1) ◽  
pp. 42-86 ◽  
Author(s):  
John C. Chao ◽  
Norman R. Swanson ◽  
Jerry A. Hausman ◽  
Whitney K. Newey ◽  
Tiemen Woutersen
Keyword(s):  
Least Squares ◽  
Instrumental Variables ◽  
Standard Errors ◽  
Asymptotic Covariance Matrix ◽  
Limited Information ◽  
Two Stage ◽  
Asymptotically Normal ◽  
Many Instruments ◽  
Two Stage Least Squares ◽  
The Many

This paper derives the limiting distributions of alternative jackknife instrumental variables (JIV) estimators and gives formulas for accompanying consistent standard errors in the presence of heteroskedasticity and many instruments. The asymptotic framework includes the many instrument sequence of Bekker (1994, Econometrica 62, 657–681) and the many weak instrument sequence of Chao and Swanson (2005, Econometrica 73, 1673–1691). We show that JIV estimators are asymptotically normal and that standard errors are consistent provided that $\root \of {K_n } /r_n \to 0$ as n→∞, where Kn and rn denote, respectively, the number of instruments and the concentration parameter. This is in contrast to the asymptotic behavior of such classical instrumental variables estimators as limited information maximum likelihood, bias-corrected two-stage least squares, and two-stage least squares, all of which are inconsistent in the presence of heteroskedasticity, unless Kn/rn→0. We also show that the rate of convergence and the form of the asymptotic covariance matrix of the JIV estimators will in general depend on the strength of the instruments as measured by the relative orders of magnitude of rn and Kn.

scholarly journals Two–Stage Instrumental Variables Identification of Polynomial Wiener Systems with Invertible Nonlinearities

2019 ◽  
Vol 29 (3) ◽  
pp. 571-580
Author(s):  
Andrzej Janczak ◽  
Józef Korbicz
Keyword(s):  
Instrumental Variables ◽  
Nonlinear Function ◽  
Estimation Accuracy ◽  
Parameter Estimates ◽  
Wiener Model ◽  
Two Stage ◽  
Linear Dynamic ◽  
Parameter Redundancy ◽  
Wiener Systems ◽  
Unique Relationship

Abstract A new two-stage approach to the identification of polynomial Wiener systems is proposed. It is assumed that the linear dynamic system is described by a transfer function model, the memoryless nonlinear element is invertible and the inverse nonlinear function is a polynomial. Based on these assumptions and by introducing a new extended parametrization, the Wiener model is transformed into a linear-in-parameters form. In Stage I, parameters of the transformed Wiener model are estimated using the least squares (LS) and instrumental variables (IV) methods. Although the obtained parameter estimates are consistent, the number of parameters of the transformed Wiener model is much greater than that of the original one. Moreover, there is no unique relationship between parameters of the inverse nonlinear function and those of the transformed Wiener model. In Stage II, based on the assumption that the linear dynamic model is already known, parameters of the inverse nonlinear function are estimated uniquely using the IV method. In this way, not only is the parameter redundancy removed but also the parameter estimation accuracy is increased. A numerical example is included to demonstrate the practical effectiveness of the proposed approach.

scholarly journals Do Government R&D Subsidies Cultivate Enterprises’ Voluntary National/Industry Standard-Setting for Sustainable Development?

2019 ◽  
Vol 11 (19) ◽  
pp. 5482
Author(s):  
Xun Zhang ◽  
Meng Shi ◽  
Biao Xu
Keyword(s):  
Sustainable Development ◽  
Instrumental Variables ◽  
Standard Setting ◽  
State Ownership ◽  
Two Stage ◽  
Research Framework ◽  
Government Subsidies ◽  
Industry Standard ◽  
National Industry ◽  
Leading Enterprises

This study investigates the effects of government subsidies for R&D on resource and environmental enterprises’ voluntary national/industry standard- (N/IS-) setting, which is critical to sustainable development. Based on innovation motivation and capability theory, we propose a research framework and hypothesis, using a panel dataset on 11,556 Chinese resource and environmental enterprises from 2011 to 2013 to test our hypotheses. We find that government subsidies for R&D have a U-shaped relationship with N/IS-setting for sustainable development. Moreover, we also find that state ownership, position in industry, and patent properties are contingency factors suggesting that non-state-owned enterprises, industry-following enterprises, or enterprises with more patents come up with N/IS-settings of significantly greater value than state-owned enterprises, leading enterprises, or enterprises with fewer patents. Endogeneity issues are addressed by utilizing two-stage estimations with instrumental variables (IVs).

One- versus two-stage transposed brachiobasilic arteriovenous fistulae: A review of the current state of the art

2019 ◽  
Vol 21 (3) ◽  
pp. 281-286 ◽  
Author(s):  
Mohamed Sheta ◽  
Jalal Hakmei ◽  
Mark London ◽  
Mathew Wooster ◽  
John Aruny ◽  
...  
Keyword(s):  
Meta Analysis ◽  
Primary Patency ◽  
Secondary Patency ◽  
Search Term ◽  
Complication Rates ◽  
Basilic Vein ◽  
Two Stage ◽  
Pubmed Search ◽  
Adequate Quality ◽  
Student’S T

In the absence of suitable cephalic vein, the brachiobasilic vein complex represents the best option for arteriovenous access. However, the basilic vein is too deep to cannulate and requires transposition to be accessible. Transposition can be performed during fistula creation (single-stage BBTx) or at a second operation after initial fistula creation (two-stage brachiobasilic transposition (BBTx)). The best approach is unknown. A PubMed search using “Basilic vein transposition” as the primary search term was performed to identify articles addressing this controversy. Meta-analysis was then performed using those papers that provided the inspected data points with student’s t-test used to compare maturation and patency rates between the groups. A total of 37 manuscripts were judged of adequate quality for analysis. Based on the available data, overall maturation rates, 1-year primary patency rates, and overall complication rates seem to be equivalent between single- and two-stage BBTx, while 1-year secondary patency is greater in the two-stage group (79% vs 85%). A large prospective randomized clinical trial with clear definitions of maturity, patency, and complications is needed to definitively answer the question of whether one strategy is better than the other.

Sign in / Sign up

Export Citation Format

Share Document