Statistical inference for a semiparametric measurement error regression model with heteroscedastic errors

Efficient inference for regression models requires that the heteroscedasticity be taken into account. We consider statistical inference under heteroscedasticity in a semiparametric measurement error regression model, in which some covariates are measured with errors. This paper has multiple components. First, we propose a new method for testing the heteroscedasticity. The advantages of the proposed method over the existing ones are that it does not need any nonparametric estimation and does not involve any mismeasured variables. Second, we propose a new two-step estimator for the error variances if there is heteroscedasticity. Finally, we propose a weighted estimating equation-based estimator (WEEBE) for the regression coefficients and establish its asymptotic properties. Compared with existing estimators, the proposed WEEBE is asymptotically more efficient, avoids undersmoothing the regressor functions and requires less restrictions on the observed regressors. Simulation studies show that the proposed test procedure and estimators have nice finite sample performance. A real data set is used to illustrate the utility of our proposed methods.     

Improving on the sample covariance matrix for a complex elliptically contoured distribution

In this paper the problem of estimating the scale matrix in a complex elliptically contoured distribution (complex ECD) is addressed. An extended Haff–Stein identity for this model is derived. It is shown that the minimax estimators of the covariance matrix obtained under the complex normal model remain robust under the complex ECD model when the Stein loss function is employed.     

行政长官及其权力运作—─香港政制系列研究之一

“九七”以后的香港政制架构中，行政长官居特殊地位，直接关系到“一国两制”方针和香港基本法的贯彻实施。本文主要是从香港特别行政区行政长官的法律地位、任职资格、产生办法、权力运作等问题的分析入手，阐明“九七”前后从港督到行政长官的转变给未来香港政制发展带来的影响，以及基本法有关规定的正确性。     

Do Lower Top Marginal Tax Rates Slow the Income Growth of Workers?

Top marginal tax rates are positively correlated with the pretax income growth of the bottom 90 per cent — those who are not subject to the top rates. To explain this correlation, this paper presents and tests a model in which executives can increase firm profitability by (i) increasing the firm's level of technology and (ii) decreasing labor costs. In the model, higher marginal tax rates may reduce pretax inequality by increasing the average income growth of workers. This hypothesis is tested by examining the effect of top marginal tax rates on (unobserved) relative bargaining power between labor and firms and, therefore, on the income growth of workers in the USA. Bargaining power, in both the theoretical and the empirical models, is proxied by private‐sector unionization and use of offshore labor resulting in higher imports.     

QUANTIFYING THE PREMIUM EXTERNALITY OF THE UNINSURED

In insurance markets, the uninsured can generate a negative externality on the insured, leading insurance companies to charge higher premia. Using a novel panel data set and a staggered policy change that introduces exogenous variation in the rate of uninsured drivers at the county level in California, we find that uninsured drivers lead to higher insurance premia: a 1 percentage point increase in the rate of uninsured drivers raises premia by roughly 1%. We calculate the monetary fine on the uninsured that would fully internalize the externality and conclude that actual fines in most US states are inefficiently low.     

THE LIMITS OF CAREER CONCERNS IN FEDERALISM: EVIDENCE FROM CHINA

Performance‐based promotion schemes in administrative hierarchies have limitations. Chinese provincial leaders, despite facing strong career concerns, make different policy decisions depending on their career backgrounds. Provincial party secretaries who have risen from low to high positions within the province they govern (“locals”) spend a higher share of budgetary resources on education and health care and invest less in construction infrastructure than party secretaries who have made their most significant career advancements in other provinces (“outsiders”). Identification comes from variation in central leadership and term limits. As the promotion mechanism rewards infrastructure investments, locals are less likely to be promoted at the end of the term. We explore various mechanisms and provide evidence that the difference between locals and outsiders is not driven by knowledge or experience. Several pieces of evidence suggest that locals cater to low‐level provincial elites, who helped them rise to power. Thus, local career trajectories limit the power of career concerns by fostering competing allegiances.     

SOVEREIGN DEBT SUSTAINABILITY IN ADVANCED ECONOMIES

We develop a measure of maximum sustainable government debt for advanced economies. How much investors are willing to lend to a country's government depends on the country's expected primary surplus, the level and volatility of its rate of growth, and how much debt the government expects to be able to raise in the future for the purpose of servicing the debt it seeks to raise today. We provide a simple formula that computes a country's maximum sustainable debt (MSD) as a function of four easy‐to‐estimate parameters. We further compute a country's theoretical probability of default (PD) as a function of its debt‐to‐GDP ratio. We finally calibrate our measures for 23 OECD countries and test the relation between sovereign yield spreads and our theoretical PD at prevailing debt levels. We find it to be strongly statistically significant.     

叙事与瞬间:再现的再研究从钱钟书与贡布里希对图画再现观点的比较说起

过贡布里希(E.H．GOMBRICH)和钱钟书对瞬间和叙事所做的阐述,进一步了解图像与眼中现实世界之间的关系,就图像或绘画再现现实的可能性进行研究。     

论张学良的和平统一观

张学良和平统一观的基本内涵是"息内争、御外侮"."息内争"与"御外侮"之间具有内在的、必然的联系,两者是相互影响、相互作用、相互制约的.这两方面共同影响着张学良政治生涯的所作所为.张学良和平统一观的形成发展过程及其实践是与其所经历的东北易帜、中原大战、西安事变等一些重大历史事件密切相关的,特定的历史时代和张学良本人与众不同的特殊经历决定了他极具特色的和平统一观.其和平统一观既具有进步性,又具有历史的局限性.     

对比分析吉特鲁德和七巧的变态反叛意识

通过对劳伦斯和张爱玲的代表作<儿子与情人>和<金锁记>中的女主人公吉特鲁德和七巧由于婚姻不幸,从天真烂漫的少女变成了变态的母亲的描述,对比分析她们身上反映出来的男权社会下的女性反叛意识.