当代美国住宅的思考

美国2000年新建住宅投资4251亿美元，占固定资产投资的21．3％；住宅直接消费为9588亿美元，占GDP的9．71％；年存量住宅为1．16亿套(户)，空置率为5．9％。购买新房一般中值价为80美元／ft^2，一套住宅(2000ft^2)中值房价为16万美元；按中值计算贷款购房的支出与收入比为1：4．7；在美国仍有3500万户居民租用住宅。     

Discussion of “How Banks' Value-at-Risk Disclosures Predict their Total and Priced Risk: Effects of Bank Technical Sophistication and Learning over Time”

Liu et al. (2004, this issue) show that technical sophistication and learning over time help improve the ability of bank trading portfolios' value-at-risk (VaR) disclosures to predict future trading income risk, and that trading VaRs predict bank-wide total risk and systematic risk. While the results suggest that VaRs are a reliable measure of risk for the sample firms, the study's incremental contribution is limited because of the nature of the sample firms and problems in variable measurement.     

土地面积和地价单位换算的简便方法

由于历史原因,我国土地面积的计量单位在不少场合仍沿用"亩"这个单位.基准地价也往往用"万元/亩"作单位.但我国土地面积的法定计量单位是"平方米".土地面积单位在"亩"与"平方米"之间以及地价在"万元/亩"与"元/平方米"之间的换算,还是土地价值评估中经常要遇到的事情.     

区域一体化有利于减排吗？

将环境污染视作非期望产出,在一个拓展的增长收敛框架下讨论了区域一体化的环境效应及其理论机制。基于2003-2014年长三角城市群和珠三角城市群的数据,构建了一个测度区域一体化的新方法,运用工具变量法和双重差分法估计了跨省城市一体化和省内城市一体化对污染排放强度收敛的影响。实证结果显示:区域一体化显著促进了城市间污染排放强度的收敛并有利于减排,且近年来这种减排效应愈明显。污染排放强度呈现出条件收敛特征,经济增长收敛是污染排放收敛的重要原因。中国应利用好区域一体化促进地区协调发展和减排的双重政策红利,进一步促进区域一体化和同城化,大力发展城市群经济,构建城市间共生互利的发展格局,实现共同减排。     

Learning minimum variance discrete hedging directly from the market

Option hedging is a critical risk management problem in finance. In the Black–Scholes model, it has been recognized that computing a hedging position from the sensitivity of the calibrated model option value function is inadequate in minimizing variance of the option hedge risk, as it fails to capture the model parameter dependence on the underlying price (see e.g. Coleman et al., J. Risk, 2001, 5(6), 63–89; Hull and White, J. Bank. Finance, 2017, 82, 180–190). In this paper, we demonstrate that this issue can exist generally when determining hedging position from the sensitivity of the option function, either calibrated from a parametric model from current option prices or estimated nonparametricaly from historical option prices. Consequently, the sensitivity of the estimated model option function typically does not minimize variance of the hedge risk, even instantaneously. We propose a data-driven approach to directly learn a hedging function from the market data by minimizing variance of the local hedge risk. Using the S&P 500 index daily option data for more than a decade ending in August 2015, we show that the proposed method outperforms the parametric minimum variance hedging method proposed in Hull and White [J. Bank. Finance, 2017, 82, 180–190], as well as minimum variance hedging corrective techniques based on stochastic volatility or local volatility models. Furthermore, we show that the proposed approach achieves significant gain over the implied BS delta hedging for weekly and monthly hedging.     

Risk Awareness of Interpersonal Trust and Entrepreneurship in China: Evidence from Survey Data

This paper aims to build a theoretical framework for the influence of risk awareness of interpersonal trust (RAIT) on entrepreneurship, and explores the influence of RAIT on entrepreneurship with the micro survey data from the Chinese General Social Survey (CGSS) 2010–2013. The study found that, individuals with higher level of RAIT, their probability of starting new business will increase significantly, and with every increase of RAIT level, the probability of business venturing increase almost 4.0%. No mediation effects of information screening and cooperative mechanism are found in the relationship between RAIT and entrepreneurship. Moreover, during the venturing process, risks accompanying interpersonal trust cannot be reduced by social input; the reduction occurs only in eastern China where the economic system and the industrial development standards are more comprehensive and mature. This paper contributes to the literatures in the following two areas: it provides new evidence on how to deal with risks in the entrepreneurship process that accompanying interpersonal trust; meanwhile, it provides an explanatory mechanism on how the risk awareness affects business venturing.     

Do environmental regulations hamper small enterprises' market entry? Evidence from China

Due to the serious increase of environmental pollution in China, environmental regulations have become significantly stringent. Such regulations are playing an increasingly important role in the development of small enterprises (SEs) in China, especially in SEs' market entry. However, existing studies pay little attention to this issue. This paper investigates for the first time the effect of environmental regulations on SEs' market entry and the mechanism of environmental regulation effects in China. We consider two sets of panel data for the periods 2003–2010 and 2012–2015 in China. We also use the fixed effect model and the instrumental variable method to explore the role of environmental regulations in SEs' market entry. The results show that, overall, environmental regulations play a significantly positive and robust role in SEs' market entry. However, the mechanisms associated with the effect of environmental regulations on different innovative types of SEs differ. Environmental regulations promote the market entry of SEs with product innovation, but this impact is not significant for SEs with research and development (R&D) activities and R&D institutions. Our findings indicate that China's SEs prefer product innovation, which is a lower level innovative type, over R&D innovation, as a means to avoid the negative impact of stringent environmental regulations.     

从意义生成角度探析女性服装品牌化——以阿依莲女装为例

从符号意义生成的三步骤探析女性服装品牌化是定性研究的一种方法。基于组合关系形成的品牌定位与品牌识别,符号的"换挡加速"完成品牌外延到品牌内涵的提升,"换挡加速"后形成多重意义下的品牌内涵凝练是阿依莲品牌符号意义生成的三步骤。其在意义生成过程中的升级,既定义了消费群,同时也界定了消费身份,赋予了消费者符号意义,完成了阿依莲产品的品牌化。     

基于SD模型的诸城市农业结构仿真优化研究

［目的］预测2017—2035年诸城市农业结构的变化趋势，对农业结构进行多情景优化仿真，提出优化调整建议。［方法］文章以山东省诸城市作为研究对象，将农业结构划分为种植、种养结合和加工休闲3个子系统，选取56个指标，运用多元统计回归分析等方法构建41个方程，建立农业结构系统动力学（System Dynamics，简称SD）模型，运用Vensim—PLE软件进行仿真优化分析。［结果］SD模型预测结果表明，到2035年，粮食作物播种面积1105万hm2，总产量8037万t，经济作物播种面积652万hm2，总产量15203万t； 生猪出栏量达到29615万头，家禽出栏量1105 231亿只，畜禽粪污利用率8792%； 农业总产值达到25132亿元，休闲农业产值6134亿元，食品加工业产值1 25263亿元。假设种植业生产中的农业科技投入增加2个百分点， 2035年粮食作物产量较优化前增加576万t； 经济作物产量较优化前增加2814万t； 假设有机肥施用补贴增加3个百分点， 2035年畜禽粪污利用率较优化前提高762个百分点； 假设农产品加工业的研发力度和科技投入增加1个百分点， 2035年食品加工产值较优化前增加73521亿元； 农产品加工业产值占农业总产值比值由优化前的325：1达到41：1。［结论］为进一步推进诸城市农业结构调整，迫切需要加大农业科技投入，完善有机肥扶持政策，培育种养结合新型经营主体，重点扶持培育加工龙头企业，发展现代化休闲农场，促进农业产业融合发展。