从美国房价走势透视中国房地产市场走向

内容文章从量化分析的角度出发,研究了全美50个州和哥伦比亚特区房价指数序列的记忆性特征,发现各州房价指数序列均具有一定程度的长记忆性.同时,我们对50个州房价指数记忆参数的估计值进行了聚类分析,由此发现各州房价指数的记忆性呈现出一定的地区聚集性特征,而且还与地区的人口密度存在一定关系,从而为宏观政策制定者在决定房价调控措施的时候提供了有益的新思维,可使楼市更加健康稳定地发展.此外,文章的研究结果对于解决我国房地产市场目前存在的巨大泡沫问题提供了一个全新的视角     

Dynamic panel cointegration approaches to the estimation of money demand functions

This paper investigates properties of the money demand functions of Group of Six (G6) member countries (Canada, France, Italy, Japan, U.K., and U.S.) using the estimation and inference techniques of panel cointegration. Empirical analyses are conducted by estimating money demand equations of G6 countries individually and as a whole, allowing heterogeneity in individual specific fixed effects across countries through dynamic, nonstationary panel estimation techniques. By using recently developed panel cointegration techniques, the paper contributes to the literature of money demand studies by improving the power performance of the relevant estimation and inference procedures. It reports fully modified OLS (FMOLS) estimation results of the money demand model for different data frequencies, to find varying signs and magnitudes of real income, interest rates and inflation elasticities of money demand for G6 nations.     

Robust estimation with flexible parametric distributions: estimation of utility stock betas

The distributions of stock returns and capital asset pricing model (CAPM) regression residuals are typically characterized by skewness and kurtosis. We apply four flexible probability density functions (pdfs) to model possible skewness and kurtosis in estimating the parameters of the CAPM and compare the corresponding estimates with ordinary least squares (OLS) and other symmetric distribution estimates. Estimation using the flexible pdfs provides more efficient results than OLS when the errors are non-normal and similar results when the errors are normal. Large estimation differences correspond to clear departures from normality. Our results show that OLS is not the best estimator of betas using this type of data. Our results suggest that the use of OLS CAPM betas may lead to erroneous estimates of the cost of capital for public utility stocks.     

Gibbs posterior inference on value-at-risk

ABSTRACT

Accurate estimation of value-at-risk (VaR) and assessment of associated uncertainty is crucial for both insurers and regulators, particularly in Europe. Existing approaches link data and VaR indirectly by first linking data to the parameter of a probability model, and then expressing VaR as a function of that parameter. This indirect approach exposes the insurer to model misspecification bias or estimation inefficiency, depending on whether the parameter is finite- or infinite-dimensional. In this paper, we link data and VaR directly via what we call a discrepancy function, and this leads naturally to a Gibbs posterior distribution for VaR that does not suffer from the aforementioned biases and inefficiencies. Asymptotic consistency and root-n concentration rate of the Gibbs posterior are established, and simulations highlight its superior finite-sample performance compared to other approaches.     

The Risk Microstructure of Corporate Bonds: A Case Study from the German Corporate Bond Market

This article presents joint econometric analysis of interest rate risk, issuer‐specific risk (credit risk) and bond‐specific risk (liquidity risk) in a reduced‐form framework. We estimate issuer‐specific and bond‐specific risk from corporate bond data in the German market. We find that bond‐specific risk plays a crucial role in the pricing of corporate bonds. We observe substantial differences between different bonds with respect to the relative influence of issuer‐specific vs. bond‐specific spread on the level and the volatility of the total spread. Issuer‐specific risk exhibits strong autocorrelation and a strong impact of weekday effects, the level of the risk‐free term structure and the debt to value ratio. Moreover, we can observe some impact of the stock market volatility, the respective stock's return and the distance to default. For the bond‐specific risk we find strong autocorrelation, some impact of the stock market index, the stock market volatility, weekday effects and monthly effects as well as a very weak impact of the risk‐free term structure and the specific stock's return. Altogether, the determinants of the spread components vary strongly between different bonds/issuers.     

政府在耕地减少中的责任和在耕地保护中的作为

集成曲线估计模型和灰色数列模型,研究耕地总量在1983-2006年间的变化过程以及在2010～2020年间的变化态势,分析政府行为在耕地总量减少中的责任和在保护耕地中的作为.研究结果:2020年耕地总量可能低于新的耕地红线,政府对耕地减少负有不可推卸的责任.     

A new energy model to capture the behavior of energy price processes

Owing to the vague fluctuation of energy prices from time to time, a new energy model, which considers both the mean-reverting behavior and the long memory property, is proposed in this paper. Since the problem of estimating parameters, in discrete time for this model, plays a central role in forecast inference, the problem of estimating the unknown parameters has been dealt with for the fractional Ornstein–Uhlenbeck process observed discretely. The asymptotic properties of these estimates are also provided. The numerical simulation results confirm the theoretical analysis and show that our method is effective. To show how to apply our approach in realistic contexts, an empirical study of energy in China, namely Daqing crude oil, is presented. The empirical results seem reasonable when compared to the real data.     

锅炉房安全设施的重要性探讨

本文主要从安全措施的设置入手,其中包括:锅炉房的设置位置、烟囱的设置、锅炉给水除氧方式、燃气供气系统、通风设备、热水循环设备、消防及报警等其他系统的设计等方面,进一步讨论锅炉房安全措施不力将导致的后果,以此对锅炉房安全措施的重要性进行深入的探讨。     

一类具有无界时滞的微分不等式

本文建立了一类具有无界时滞微分不等式,将有界时滞微分不等式推广到无界时滞微分不等式,并得到其解的指数估计和渐近估计.     

Information Technology As A Factor Of Production: The Role Of Differences Among Firms

Despite evidence that information technology (IT) has recently become a productive investment for a large cross-section of firms, a number of questions remain. Some of these issues can be addressed by extending the basic production function approach that was applied in earlier work. Specifically, in this short paper we: 1) control for individual firm differences in productivity by employing a ‘firm effects’ specification, 2) consider the more flexible translog specification instead of only the Cobb-Douglas specification, and 3) allow all parameters to vary between various subsectors of the economy.

We find that while ‘firm effects’ may account for as much as half of the productivity benefits imputed to IT in earlier studies, the elasticity of IT remains positive and statistically significant. We also find that the estimates of IT elasticity and marginal product are little-changed when the less restrictive translog production function is employed. Finally, we find only limited evidence of differences in IT's marginal product between manufacturing and services and between the ‘measurable’ and ‘unmeasurable’ sectors of the economy. Surprisingly, we find that the marginal product of IT is at least as high in firms that did not grow during 1988–1992 sample period as it is in firms that grew.