Estimation of covariance matrices in fixed and mixed effects linear models

AbstractThe estimation of the covariance matrix or the multivariate components of variance is considered in the multivariate linear regression models with effects being fixed or random. In this paper, we propose a new method to show that usual unbiased estimators are improved on by the truncated estimators. The method is based on the Stein–Haff identity, namely the integration by parts in the Wishart distribution, and it allows us to handle the general types of scale-equivariant estimators as well as the general fixed or mixed effects linear models

Asymptotically optimal tests for parametric functions against ordered functional alternatives

There are hypothesis testing problems for (nonlinear) functions of parameters against functional ordered alternatives for which a reduction to a conventional order-restricted hypothesis testing problem may not be feasible. While such problems can be handled in an asymptotic setup, among the available choices, it is shown that the union-intersection principle may have certain advantages over the likelihood principle or its ramifications. An application to a genomic model is also considered

On inadmissibility of Hotelling T2-tests for restricted alternatives

For multinormal distributions, testing against a global shift alternative, the Hotelling T2-test is uniformly most powerful invariant, and hence admissible. For testing against restricted alternatives this feature may no longer be true. It is shown that whenever the dispersion matrix is an M-matrix, Hotelling's T2-test is inadmissible, though some union-intersection tests may not be so

Nexus Between Official Development Aid, Institutional Quality and Economic Growth: Evidence from CLMV countries

This study examines the effect of country-specific Official Development Aid (ODA) and institutional quality on economic growth for Cambodia, Laos, Myanmar, and Vietnam (CLMV) countries from 2002 to 2017. Our results indicate that: First, the impact of ODA from Germany, Japan and France on economic growth is conditional on the level of institutional quality of CLMV countries. The ODA has a negative impact on growth when institutional quality is low. Beyond a threshold of institutional quality, ODA promotes economic growth. Second, the results are robust after controlling for outliers and endogeneity in the model. Third, the further analysis provides evidence that the mitigating effect of institutional quality works through both labour productivity and human capital growth channel. Based on the findings, this study offers some imperative policy recommendations to both donor countries and ODA recipients

Impact of Foreign Exchange Administration Rule on the Nexus between Country-Specific FDI and Malaysian Currency

In the aftermath of the US Presidential election on 8 November 2016, the Malaysian currency Ringgit (MYR) had witnessed unprecedented volatility in its value relative to the USD. As a policy response, Bank Negara Malaysia (BNM) implemented a Supplemental Foreign Exchange Administration (SFEA) Rule in December 2016. Exporters are required to convert 75 per cent of foreign currency proceeds from the exports of goods into MYR with a licensed onshore bank. This study evaluates the impact of the new SFEA Rule on the relationship between country-specific FDI and MYR. Based on the data of five major inward FDI countries from 2015 to 2018, our results show: Firstly, Japanese FDI strengthens MYR in post-SFEA Rule; Secondly, FDI from Singapore is found to exert downward pressure on MYR; Thirdly, FDI from China, the Netherlands and the US are insignificant in influencing the MYR; Finally, inward FDI from different countries responds differently to the Rule. Notably, the results obtained are robust to different measures of the exchange rate. On policy suggestion, the Foreign Exchange Rule should also target non-export oriented inward FDIs to achieve the policy target. The result also highlights the importance of export-oriented FDIs for the long-run benefit of the Malaysian economy

Two-Stage Likelihood Ratio and Union–Intersection Tests for One-Sided Alternatives Multivariate Mean with Nuisance Dispersion Matrix

For a multinormal distribution with an unknown dispersion matrix, union-intersection (UI) tests for the mean against one-sided alternatives are considered. The null distribution of the UI test statistic is derived and its power monotonicity properties are studied. A Stain-type two-stage procedure is proposed to eliminate some of the inherent drawbacks of such tests. Some comparisons are also made with some recently proposed alternative conditional likelihood ratio tests

Locally best rotation-invariant rank tests for modal location

For a general class of unipolar, rotationally symmetric distributions on the multi-dimensional unit spherical surface, a characterization of locally best rotation-invariant test statistics is exploited in the construction of locally best rotation-invariant rank tests for modal location. Allied statistical distributional problems are appraised, and in the light of these assessments, asymptotic relative efficiency of a class of rotation-invariant rank tests (with respect to some of their parametric counterparts) is studied. Finite sample permutational distributional perspectives are also appraised

INFORMATION FLOW BETWEEN THE US DOLLAR-RUPIAH EXCHANGE RATES

This study investigates the information flow between non-deliverable forward (NDF), spot, and forward US dollar–rupiah exchange rates during the post-Quantitative Easing (QE) period. Our results show a unidirectional information flow from NDF to the spot and forward rates in the post-QE period. We also find that the Indonesian government securities (IGS) played a vital role during the QE period, while international reserves preceded the US dollar–rupiah spot, forward, and NDF exchange rates post-QE. Hence, international reserves became an important policy variable in managing the currency value. Our finding redefines the role of IGS as a policy tool. As a policy suggestion, the Bank Indonesia should maintain a sufficient amount of foreign reserves to mitigate foreign exchange risks of the rupiah.This study investigates the information flow between non-deliverable forward (NDF), spot, and forward US dollar–rupiah exchange rates during the post-Quantitative Easing (QE) period. Our results show a unidirectional information flow from NDF to the spot and forward rates in the post-QE period. We also find that the Indonesian government securities (IGS) played a vital role during the QE period, while international reserves preceded the US dollar–rupiah spot, forward, and NDF exchange rates post-QE. Hence, international reserves became an important policy variable in managing the currency value. Our finding redefines the role of IGS as a policy tool. As a policy suggestion, the Bank Indonesia should maintain a sufficient amount of foreign reserves to mitigate foreign exchange risks of the rupiah

Locally best rotation-invariant rank tests for modal location

For a general class of unipolar, rotationally symmetric distributions on the multi-dimensional unit spherical surface, a characterization of locally best rotation-invariant test statistics is exploited in the construction of locally best rotation-invariant rank tests for modal location. Allied statistical distributional problems are appraised, and in the light of these assessments, asymptotic relative efficiency of a class of rotation-invariant rank tests (with respect to some of their parametric counterparts) is studied. Finite sample permutational distributional perspectives are also appraised