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Mohammad W. Hattab

Publications and source records attributed to Mohammad W. Hattab.

2 recordsLinked to original sources

A Two Stage Quasi-Likelihood Estimation Method for High Dimensional Generalized Structural Equation Models

Estimating high dimensional Generalized Structural Equation Models presents severe computational challenges. Traditional simultaneous estimators frequently suffer from numerical instability and prohibitive computational costs. Moreover, there are no tractable algorithms for families such as Poisson, negative binomial, and gamma. To overcome these limitations, this article introduces a Two Stage Quasi-Likelihood Expectation-Maximization framework. The proposed method isolates the structural model from the measurement model. First, it approximates the conditional distribution of the latent variables given the observed indicators. Second, it employs marginal quasi-likelihood estimating equations to evaluate the structural parameters, deriving the necessary conditional moments either exactly or through Monte Carlo integration. This approach completely avoids the need to evaluate the full joint likelihood. Extensive simulations demonstrate that our method drastically reduces computational runtime, providing a numerically stable framework that minimizes the mean squared error and structural bias to yield a scalable and flexible solution for analyzing complex latent variable models.

stat.ME↗

Measurement Errors in Semiparametric Generalized Regression Models

Regression models that ignore measurement error in predictors may produce highly biased estimates leading to erroneous inferences. It is well known that it is extremely difficult to take measurement error into account in Gaussian nonparametric regression. This problem becomes tremendously more difficult when considering other families such as logistic regression, Poisson and negative-binomial. For the first time, we present a method aiming to correct for measurement error when estimating regression functions flexibly covering virtually all distributions and link functions regularly considered in generalized linear models. This approach depends on approximating the first and the second moment of the response after integrating out the true unobserved predictors in a semiparametric generalized linear model. Unlike previous methods, this method is not restricted to truncated splines and can utilize various basis functions. Through extensive simulation studies, we study the performance of our method under many scenarios.

stat.ME↗