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Full-Text Articles in Social and Behavioral Sciences
Diagnostic Tests For Homoskedasticity In Spatial Cross-Sectional Or Panel Models, Badi K. Baltagi, Alain Pirotte, Zhenlin Yang
Diagnostic Tests For Homoskedasticity In Spatial Cross-Sectional Or Panel Models, Badi K. Baltagi, Alain Pirotte, Zhenlin Yang
Research Collection School Of Economics
We propose an Adjusted Quasi-Score (AQS) method for constructing tests for homoskedasticity in spatial econometric models. We first obtain an AQS function by adjusting the score-type function from the given model to achieve unbiasedness, and then develop an Outer-Product-of-Martingale-Difference (OPMD) estimate of its variance. In standard problems where a genuine (quasi) score vector is available, the AQS-OPMD method leads to finite sample improved tests over the usual methods. More importantly in non-standard problems where a genuine (quasi) score is not available and the usual methods fail, the proposed AQS-OPMD method provides feasible solutions. The AQS tests are formally derived and …
Spatial Panel Data Models With Temporal Heterogeneity, Yuhong Xu
Spatial Panel Data Models With Temporal Heterogeneity, Yuhong Xu
Dissertations and Theses Collection (Open Access)
This dissertation studies the fixed effects (FE) spatial panel data (SPD) models with temporal heterogeneity (TH), where the regression coefficients and spatial coefficients are allowed to change with time. The FE-SPD model with time-varying coefficients renders the usual transformation method in dealing with the fixed effects inapplicable, and an adjusted quasi score (AQS) method is proposed, which adjusts the concentrated quasi score function with the fixed effects being concentrated out. AQS tests for the lack of temporal heterogeneity (TH) in slope and spatial parameters are first proposed. Then, a set of AQS estimation and inference methods for the FE-SPD model …
Robust Estimation And Inference Of Spatial Panel Data Models With Fixed Effects, Shew Fan Liu, Zhenlin Yang
Robust Estimation And Inference Of Spatial Panel Data Models With Fixed Effects, Shew Fan Liu, Zhenlin Yang
Research Collection School Of Economics
It is well established that the quasi maximum likelihood (QML) estimation of the spatial regression models is generally inconsistent under unknown cross-sectional heteroskedasticity (CH) and the CH-robust methods have been developed. The same issue remains for the spatial panel data (SPD) models but the similar studies based on QML approach do not seem to have been carried out. This paper focuses on the SPD model with fixed effects (FE). We argue that under unknown CH the QML estimator for the SPD-FE model is inconsistent in general, but there are ‘special cases’ where it may remain consistent although the exact conditions …
Estimation Of Fixed Effects Spatial Dynamic Panel Data Models With Small T And Unknown Heteroskedasticity, Liyao Li, Zhenlin Yang
Estimation Of Fixed Effects Spatial Dynamic Panel Data Models With Small T And Unknown Heteroskedasticity, Liyao Li, Zhenlin Yang
Research Collection School Of Economics
We consider the estimation and inference of fixed effects (FE) spatial dynamic panel data (SDPD) models under small T and unknown heteroskedasticity by extending the M-estimation strategy for homoskedastic FE-SDPD model of Yang (2018, Journal of Econometrics). Unbiased estimating equations are obtained by adjusting the conditional quasi-score functions given the initial observations, leading to M-estimators that are free from the initial conditions and robust against unknown cross-sectional heteroskedasticity. Consistency and asymptotic normality of the proposed M-estimator are established. The standard errors are obtained by representing the estimating equations as sums of martingale differences. Monte Carlo results show that the proposed …
Specification Tests For Temporal Heterogeneity In Spatial Panel Data Models With Fixed Effects, Yuhong Xu, Zhenlin Yang
Specification Tests For Temporal Heterogeneity In Spatial Panel Data Models With Fixed Effects, Yuhong Xu, Zhenlin Yang
Research Collection School Of Economics
We propose adjusted quasi score (AQS) tests for testing the existence of temporal heterogeneity in slope and spatial parameters in spatial panel data (SPD) models, allowing for the presence of individual-specific and/or time-specific fixed effects (or in general intercept heterogeneity). The SPD model with spatial lag is treated in detail by first considering the model with individual fixed effects only, and then extending it to the model with both individual and time fixed effects. Two types of AQS tests (naïve and robust) are proposed, and their asymptotic properties are presented. These tests are then fully extended to SPD models with …