On estimation of the scale matrix of the multivariate f distribution

Let F _p×phave a multivariate F distribution with a scale p×p matrix Δ and degrees of freedom k₁ and k₂ such that k_i - p - 1 > 0, i = 1,2. The estimation of Δ under entropy and squared error loss functions are considered. In both cases a new class of orthogonally invariant estimators are obtained which dominate the best unbiased estimator.     

A matching prior based on the modified profile likelihood in a generalized Weibull stress‐strength model

Bayesian inference of a generalized Weibull stress‐strength model (SSM) with more than one strength component is considered. For this problem, properly assigning priors for the reliabilities is challenging due to the presence of nuisance parameters. Matching priors, which are priors matching the posterior probabilities of certain regions with their frequentist coverage probabilities, are commonly used but difficult to derive in this problem. Instead, we apply an alternative method and derive a matching prior based on a modification of the profile likelihood. Simulation studies show that this proposed prior performs well in terms of frequentist coverage and estimation even when the sample sizes are minimal. The prior is applied to two real datasets. The Canadian Journal of Statistics 41: 83–97; 2013 © 2012 Statistical Society of Canada     

A Small Sample Test for the Equality of Intraclass Correlation Coefficients Under Unequal Family Sizes for Several Populations

The set of all distinct blocks of a BIBD(v,b,r,k,λ) is referred to as the support of the design. In this paper, the family of BIB designs with v=9 and k=3 is studied from the view of possible support sizes, b*'s. A table is constructed of designs with support sizes belonging to {12,18,20,21,…,84}, for minimum possible b in each case and for any larger admissible b. In constructing this table the methods of trade-off and composition of designs are utilized     

Commodities and monetary policy: Implications for inflation and price level targeting

We examine the relative ability of inflation targeting and price level targeting monetary policy rules to minimize inflation variability and business cycle fluctuations in a commodity-exporting country for supply and demand shocks to global commodity markets. The macroeconomic consequences of oil and non-oil primary commodities differ and affect the relative merits of the alternative monetary policy frameworks. Particularly, the consumption of refined oil products and demand-driven commodity price movements induce highly persistent inflation pressures resulting in a significant deterioration of the inflation-output gap trade-off available to central banks. When such terms-of-trade shocks are prevalent, price level targeting is inferior to inflation targeting.     

Effectiveness of policy interventions during financial crises in China and Russia: Lessons for the COVID-19 pandemic

We test the hypothesis that policy interventions in crisis periods are less effective when markets are integrated, drawing on China and Russia’s experience during the global financial crisis. We conduct an event study to examine the response of stock market returns and volatility to intervention efforts using DCC-GARCH and Markov Regime Switching Models. We then estimate the extent of integration of China and Russia with the US market and assess its impact on policy interventions’ effectiveness based on a regression framework. We find that interventions were effective in China but failed in Russia, where greater global links were evident. Our findings provide important policy lessons to address the impact of the current COVID-19 pandemic, given the increasing global market linkages.     

Remittances,financial development and poverty reduction in Sub-Saharan Africa: Implications for post-COVID-19 macroeconomic policies

To design and implement effective post-COVID-19 macroeconomics policies to tackle poverty in sub-Saharan Africa (SSA), policymakers need to understand the factors shaping poverty in the region. This paper investigates the effect of international remittances and financial development on poverty alleviation in 44 sub-Saharan African SSA countries from 2010 to 2019. The instrumental variable generalised method of moment technique results indicated that while remittances increase poverty, financial development contributes significantly to poverty reduction. The results consistently revealed that remittances increase both male and female poverty rates, while financial development significantly reduces male and female poverty rates. Other factors such as economic growth, foreign direct investment, and trade openness contributed significantly to reducing poverty. In contrast, government expenditure and foreign aid were found to increase poverty rate in SSA. These results are robust to the Lewbel two-stage least squares estimator. The practical implications of these findings for post-COVID-19 macroeconomic policies in SSA are discussed.     

Financial Globalization and the Governance of Domestic Financial Intermediaries

We model a small open economy in which both domestic financial intermediaries and entrepreneurs face incentive constraints, as in Holmstrom and Tirole (1997) , to study the general equilibrium impact of various types of capital inflows on the efficiency and governance of domestic banks. Banks have an advantage in monitoring firms, but the latter can collude with banks and offer side‐payments to reduce the intensity of monitoring. Opening up to international capital flows makes domestic banks’ capital scarcer relative to uninformed capital, thus increasing the relative cost of monitoring. We show that capital account liberalization has ambiguous effects on the governance of the domestic financial system by sometimes increasing firms’ incentives to collude with banks. We characterize the conditions under which governance is more likely to deteriorate after opening up the capital account, and discuss the effects on investment, productivity and output. We also analyze the effects of foreign direct investment in the corporate and banking sectors. Stylized facts are consistent with the predictions of the model.     

“呀呀语”音高母语倾向之实验研究

本项研究通过对2名长沙儿童的长期跟踪调查研究得来的实验数据进行语音实验和量化分析对比,发现儿童呀呀语阶段的音高模式呈现目标语成人语言的声调特征。实验证明了声调语言环境中的儿童呀呀语音高发展受目标语声调的影响并呈现一定的规律,有力的反驳了雅柯布森非连贯性假设。     

CRITICAL PERIODS DURING CHILDHOOD AND ADOLESCENCE

We identify the ages that constitute sensitive (or critical) periods in children's development towards their adult health status, skills, and human capital. For this, we use data on families migrating into Sweden from countries that are poorer, with less healthy conditions. Late‐life health is proxied by adult height and other adult outcomes. The relation between siblings’ ages at migration and their adult outcomes allows us to estimate the causal effect of conditions at specific childhood ages. We effectively exploit that, for siblings, the migration occurs simultaneously in calendar time but at different developmental stages (ages). We find evidence that the period just before the puberty growth spurt constitutes a critical period for adult height and we find related critical periods for adult cognition, mental health, and education.