基于混频已实现GARCH模型的波动预测与VaR度量

本文将Hansen等（2012）的Realized GARCH模型扩展为包含日内收益率、日收益率以及已实现波动率的混频已实现GARCH模型（M-Realized GARCH模型）。该模型将日内交易分为前后两段,引入了混频均值方程,并对混频均值方程的残差分别建立条件波动率方程和已实现日波动率方程。本文采用2013-2016年沪深300指数混频数据,分别在扰动项服从正态分布、t分布和广义误差分布的假设下,采用损失函数、SPA检验、kupiec检验和动态分位数检验法,对GARCH、Realized GARCH和M-Realized GARCH模型的波动率预测和VaR度量效果对比研究,得出M-Realized GARCH模型能提高预测精度,且VaR实际失败率与理论失败率一致,失败发生之间不相关。最后,本文利用Block bootstrap方法抽样得到混频数据,模拟证明了M-Realized GARCH模型比Realized GARCH模型具有更高的预测精度。     

D-optimal block designs with at most six varieties

For given positive integers v, b, and k (all of them ≥2) a block design is a k × b array of the variety labels 1,…,v with blocks as columns. For the usual one-way heterogeneity model in standard form the problem is studied of finding a D-optimal block design for estimating the variety contrasts, when no balanced block design (BBD) exists. The paper presents solutions to this problem for v≤6. The results on D-optimality are derived from a graph-theoretic context. Block designs can be considered as multigraphs, and a block design is D-optimal iff its multigraph has greatest complexity (=number of spanning trees).     

旧城更新叙事的权力维度和理念维度——以上海“田子坊”为例

过去二十年,上海旧城改造最有名的项目之一是田子坊。田子坊做得有声有色,却非一帆风顺,它曾多次面临被拆迁的危机。田子坊求生存的斗争既是政府内部关乎开发主导的权力之争,更是城市更新的模式之争和城市发展的理念之争。田子坊实验的艰难,在于它是从政府内部对城市更新主导模式的认真质疑,及对更好兼顾城市文脉、创新产业、居民利益和社会公正的包容性改造新模式的真诚实践。田子坊可能成为孤独的成功者,但田子坊的经验和原则不应成为孤案,而应得到充分的肯定并在未来城市的更新中得以大力地推广。     

FDR control under block dependence

In practical settings such as microarray data analysis, multiple hypotheses with dependence within but not between equal-sized blocks often need to be tested. We consider an adaptive BH procedure to test the hypotheses. Under the condition of positive regression dependence on a subset of the true null hypotheses, the proposed adaptive procedure is shown to control the false discovery rate. The proposed approach is compared to the existing methods in simulation under block dependence and totally uniform pairwise dependence. It is observed that the proposed method performs better than the existing methods in several situations.     

Optimal block designs for three treatments when observations are correlated

E$E$-optimal designs for comparing three treatments in blocks of size three are identified, where intrablock observations are correlated according to a first order autoregressive error process with parameter ρ∈(0,1)$\rho \in (0,1)$. For number of blocks b   of the form b=3n+1$b=3n+1$, there are two distinct optimal designs depending on the value of ρ$\rho$, with the best design being unequally replicated for large ρ$\rho$. For other values of b$b$, binary, equireplicate designs with specified within-block assignment patterns are best. In many cases, the stronger majorization optimality is established.     

State implementation of TANF: where do we stand in 2001?

To provide a context for understanding the evaluations discussed in this volume, this paper gives an overview of the federal TANF legislation and describes features of state TANF programs that are particularly relevant for appreciating the need for evaluation and for interpreting evaluations. These features include the states’ policies regarding work by applicants and recipients, policies to divert applicants from welfare, and rules designed to change individuals’ behavior regarding childbearing, childrearing, and marriage. Because the implementation of state policies depends on practices at the front lines of the welfare system, some features of the ‘culture’ of local welfare offices are also examined.     

中国经济波动的外部因素：1992-2008

 文章讨论包括国际石油价格、世界利率、美元汇率和国外需求的外部因素冲击对中国宏观经济波动的影响。运用含外生变量的结构向量自回归模型进行计量分析,结果表明：外部冲击是中国宏观经济波动的重要来源;供给冲击与需求冲击作用相当,但后者对中国经济波动起着持久性作用;金融危机期间,需求冲击比供给冲击更重要。政策内涵是：宏观经济调控依据国内外经济动态变化相机调整,扩大国内需求,缓解国外需求对宏观经济的持久性冲击。说明在国际金融危机冲击下,需实施扩张性财政政策替代萎缩的私人投资刺激内需。     

区块链技术对国民经济核算发展的影响

区块链在记账技术方面实现了重大创新,从根本上影响了国民经济核算的发展方向。本文从改变工商会计数据基础、重新界定数据资产权益、金融中介服务去中心化以及大规模开发应用微观数据等几个角度探讨了区块链技术重大突破对国民经济核算发展的影响。本文认为,为了适应区块链技术的发展,国民经济核算应在改变机构单位和基层单位的划分方法、扩展数据生产边界、拓展数据资产核算范围、完善金融产出和金融资产处理方法、加强跨境经济活动核算等方面进一步优化创新。     

Two-Level Designs in Blocks of Size Two in Which All Main Effects and Two-Factor Interactions Are Estimable

There are many problems in the real world for which it is necessary to perform two points in one block. In this situation, information about certain treatments may be indistinguishable from, or confounded with, blocks. If the experimenter wants to estimate all main effects and two-factor interactions in which two points are in one block, then how to perform the blocking schemes is an important topic to study. In this article, we combine several 2 ^k?p fractions from same or different family to obtain better combined designs requiring fewer runs than those appearing in the literature.