土地市场扭曲如何影响制造业出口产品质量升级*——基于土地市场交易数据和制造业企业数据的实证分析

地方政府“以地谋发展”的策略在促进各地区制造业大规模集聚和出口贸易快速增长的同时，也势必会给企业出口产品质量带来深刻影响。本文综合利用中国土地市场网城市土地交易数据、中国工业企业数据、中国海关进出口产品数据和中国城市面板数据，实证检验了土地市场扭曲对企业出口产品质量升级的影响，并对其内在机制进行了探讨。研究发现：中国城市建设用地配置存在明显的工业偏向性，进而导致工业用地价格被低估，产生工业用地应得收益大于实际价格的反向扭曲问题。这种反向扭曲可通过抑制技术进步、阻碍产业结构高级化、弱化集聚经济效应等机制显著降低制造业企业出口产品质量。土地市场扭曲对企业出口产品质量升级的影响具有明显的异质性特征。具体而言，土地市场扭曲不利于一般贸易企业与混合贸易企业出口产品质量提升，但对加工贸易企业出口产品质量提升具有促进作用。土地市场扭曲对企业出口产品质量升级的抑制作用由东到西依次递增。土地市场扭曲不利于外资企业和国有企业出口产品质量提升，对集体企业及民营企业的影响不显著。     

Farm Capital Investment and Deviations from the Optimal Path

We identify farms’ optimal investment path in capital assets and compare it with their actual investment to assess the direction and extent of deviation from the optimal investment. A probit model is further used to investigate the determinants of the probability that a farmer over‐ or under‐invests in capital assets. We use a panel dataset of Dutch dairy farms over the period 2003–2013, and find that most farms under‐invest in capital assets during the study period. Although the number of farms that had over‐invested in capital assets is relatively small, these farms account for the biggest share of total investment in capital assets. The probit results show that liquidity, agricultural support payments, age, land tenure and standard output size are important variables explaining the likelihood of over‐and under‐investment.     

Improving forecasting performance using covariate-dependent copula models

Copulas provide an attractive approach to the construction of multivariate distributions with flexible marginal distributions and different forms of dependences. Of particular importance in many areas is the possibility of forecasting the tail-dependences explicitly. Most of the available approaches are only able to estimate tail-dependences and correlations via nuisance parameters, and cannot be used for either interpretation or forecasting. We propose a general Bayesian approach for modeling and forecasting tail-dependences and correlations as explicit functions of covariates, with the aim of improving the copula forecasting performance. The proposed covariate-dependent copula model also allows for Bayesian variable selection from among the covariates of the marginal models, as well as the copula density. The copulas that we study include the Joe-Clayton copula, the Clayton copula, the Gumbel copula and the Student’s $t$-copula. Posterior inference is carried out using an efficient MCMC simulation method. Our approach is applied to both simulated data and the S&P 100 and S&P 600 stock indices. The forecasting performance of the proposed approach is compared with those of other modeling strategies based on log predictive scores. A value-at-risk evaluation is also performed for the model comparisons.     

The antecedents of tourists’ gaming spend: does the brand prestige matter?

This study endeavors to empirically analyse the influential effect among brand prestige, service quality, casino visitor satisfaction and spend. Data from 304 tourists who had travelled to Macau and had participated in gambling activities were used and structural equation modelling and multi-group analysis were employed in hypotheses testing. The findings demonstrated that both brand prestige and perceived service quality are determinants of satisfaction and gaming spend, and that brand prestige also affects service quality positively. Furthermore, past experience moderates the service quality and visitors’ satisfaction relationship, also service quality and visitors’ gaming spend relationship.     

Competing with complementors: An empirical look at Amazon.com

Research Summary : Platform owners sometimes enter complementors' product spaces and compete against them. Using data from Amazon.com to study Amazon's entry pattern into third‐party sellers' product spaces, we find that Amazon is more likely to target successful product spaces. We also find that Amazon is less likely to enter product spaces that require greater seller efforts to grow, suggesting that complementors' platform‐specific investments influence platform owners' entry decisions. While Amazon's entry discourages affected third‐party sellers from subsequently pursuing growth on the platform, it increases product demand and reduces shipping costs for consumers. We consider the implications of these findings for complementors in platform‐based markets. Managerial Summary : Platform owners can exert considerable influence over their complementors' welfare. Many complementors with successful products are pushed out of markets because platform owners enter their product spaces and compete directly with them. To mitigate such risks, complementors could build their businesses by aggregating nonblockbuster products or focusing on products requiring significant platform‐specific investments to grow. They should also develop capabilities in new product discovery so that they could continually bring innovative products to their platforms.     

中国北方大规模生猪养殖技术效率研究

[目的]通过对我国北方地区大规模生猪养殖技术效率进行测度,以期发现影响其技术效率增长的主要因素,为我国现阶段生猪养殖业战略性区划调整"南猪北进"工作提供实践指导和理论支持。[方法]根据随机前沿分析方法 (SFA)基本原理,运用对数型柯布—道格拉斯生产函数及我国北方大规模生猪养殖数据构建中国北方大规模生猪养殖随机前沿分析模型,对我国北方大规模生猪养殖技术效率进行测度并据此提出相关建议。[结果]北方地区大规模生猪养殖技术效率值纵向上来看整体在不断下降,而从地域上来看内蒙古自治区和东北地区技术效率值较高,北京与西北地区技术效率值较低。[结论]内蒙古自治区与东北地区适宜作为大规模生猪养殖承载地,与国家政策具有一致性;华北地区与西北地区大规模生猪养殖技术效率测度值较低,存在较大改进空间;针对该现状提出构建经济效益与环境保护并重的规模生态生猪养殖体系。     

Volatility forecasting: long memory,regime switching and heteroscedasticity

In this article, we account for the first time for long memory, regime switching and the conditional time-varying volatility of volatility (heteroscedasticity) to model and forecast market volatility using the heterogeneous autoregressive model of realized volatility (HAR-RV) and its extensions. We present several interesting and notable findings. First, existing models exhibit significant nonlinearity and clustering, which provide empirical evidence on the benefit of introducing regime switching and heteroscedasticity. Second, out-of-sample results indicate that combining regime switching and heteroscedasticity can substantially improve predictive power from a statistical viewpoint. More specifically, our proposed models generally exhibit higher forecasting accuracy. Third, these results are widely consistent across a variety of robustness tests such as different forecasting windows, forecasting models, realized measures, and stock markets. Consequently, this study sheds new light on forecasting future volatility.     

大豆大杂粉碎及重杂灭活工艺改造

随着国家对环保的重视,改变进口大豆大杂(豆荚、豆杆)焚烧处理的传统做法尤为重要,采用风选、粉碎等手段,区分处理轻重杂,杂质分别采用生产线高温高压和蒸汽湿热灭活法进行处理后,可充当纤维类物质掺入到成品豆粕中。根治环境污染的同时降低厂内安全风险,充分利用进口大豆秸秆类纤维物质,减少大豆损耗,以较小的投入实现经济效益和环境保护。     

微波加热对叶绿素水溶液的影响

本文通过对叶绿素水溶液进行微波加热,分析微波加热对叶绿素水溶液的温度、色度、叶绿素含量的影响。结果表明,微波加热处理的水溶液温度显著高于对照沸水浴,1~2 min时,1000 W功率下的水溶液温度显著高于200 W(P<0.05)。与沸水浴相比,微波加热显著降低了叶绿素水溶液的绿色程度,且高功率微波加热显著加剧了水溶液亮度的变化。200 W微波加热使水溶液中叶绿素a、b含量降低,但1000 W微波加热则提高了水溶液中叶绿素a、b含量。