Stochastic Technology, Risk Preferences, and Adoption of Site-Specific Technologies

A model of farmer decision making is developed to determine the extent to which uncertainties about soil fertility and weather affect the value of site-specific technologies (SSTs) using jointly estimated risk and technology parameters. Uncertainty can lead risk-averse farmers to apply more fertilizers and generate more pollution than in the certainty case. Ignoring uncertainty and risk aversion would overestimate the economic and environmental benefits of SSTs and underestimate the subsidy required to induce adoption. Accounting for uncertainties and risk preferences might explain the low observed adoption rates of SSTs. Improving the accuracy of SSTs would increase the incentives for adoption.     

城市交通与城市空间结构演变

通过回顾城市交通和城市空间结构的发展演变过程,研究通过城市交通引导城市空间结构健康"生长"的有效途径,提出通过公共交通引导城市发展的TOD模式,以及适合中国特色的和谐城市形态和城市交通.     

Does economic policy uncertainty drive the dynamic spillover among traditional currencies and cryptocurrencies? The role of the COVID-19 pandemic

The paper examines the dynamic spillover among traditional currencies and cryptocurrencies before and during the COVID-19 pandemic and investigates whether economic policy uncertainty (EPU) impacts this spillover. Based on the TVP-VAR approach, we find evidence of spillover effects among currencies, which increased widely during the pandemic. In addition, results suggest that almost all cryptocurrencies remain as “safe-haven” tools against market uncertainty during the COVID-19 period. Moreover, comparative analysis shows that the total connectedness for cryptocurrencies is lower than for traditional currencies during the crisis. Further analysis using quantile regression suggests that EPU exerts an impact on the total and the net spillovers with different degrees across currencies and this impact is affected by the health crisis. Our findings have important policy implications for policymakers, investors, and international traders.     

绿色普惠金融与乡村振兴耦合能否助推经济发展？

基于2011—2020年中国30个省（自治区、直辖市）的相关面板数据,利用耦合协调度和空间回归模型,分析绿色普惠金融与乡村振兴耦合协调发展水平并进一步探讨其对经济的助推作用。结果表明：绿色普惠金融与乡村振兴之间存在耦合协调机制;无论在经济空间还是地理空间中,某一地区的耦合协调度均可以促进本地及周边地区经济增长;在东、中、西部区域中,耦合协调度的经济效应具备空间外溢性和地区异质性。基于此,提出在全国范围内整体提升耦合协调度、在不同区域内立足区域实际进行精准施策的建议。     

产业组织角度的合作R＆D研究述评

合作R＆D是企业整合研发资源的有效组织形式。本文对产业组织角度的合作R＆D研究进行了较为细致的综述。首先列举了对合作R＆D理论具有一定影响的经验研究；然后梳理了产业组织角度的合作R＆D主流理论；之后介绍了较有代表性的非主流理论研究；最后是全文结论和留待进一步研究的论题。     

溢出效应、边界选择与产业集聚测度

产业集聚程度的测度结果受所选产业加总水平与地理单元大小的影响,后者应以集聚过程中溢出效应的产业边界与空间边界为基础。当前产业集聚测度研究普遍存在产业加总水平与地理单元选择过大的问题,本文试图研究在这种情况下测度结果是否存在偏差,偏差的系统性、方向、大小和影响因素,以及有偏的测度结果对集聚经济研究的影响等。结果表明,超出空间边界或产业边界的测度结果将显著偏低,并导致对集聚经济的低估;按省测度的区位基尼系数比按市测度平均低了近40%,两位数产业的区位基尼系数通常低于其所含三位数产业的区位基尼系数的均值,甚至最低值。     

Multivariate volatility forecasts for stock market indices

Volatility forecasts aim to measure future risk and they are key inputs for financial analysis. In this study, we forecast the realized variance as an observable measure of volatility for several major international stock market indices and accounted for the different predictive information present in jump, continuous, and option-implied variance components. We allowed for volatility spillovers in different stock markets by using a multivariate modeling approach. We used heterogeneous autoregressive (HAR)-type models to obtain the forecasts. Based an out-of-sample forecast study, we show that: (i) including option-implied variances in the HAR model substantially improves the forecast accuracy, (ii) lasso-based lag selection methods do not outperform the parsimonious day-week-month lag structure of the HAR model, and (iii) cross-market spillover effects embedded in the multivariate HAR model have long-term forecasting power.     

美联储前瞻性指引对新兴市场国家的溢出效应研究

基于前瞻性指引溢出效应的相关理论,选取17个代表性新兴市场国家为研究对象,运用面板向量自回归(PVAR)模型实证分析美联储前瞻性指引对新兴市场国家的溢出效应.结果表明:美联储前瞻性指引在短期内对新兴市场国家金融市场具有一定的冲击,在长期内对新兴市场国家经济增长存在滞后的正向作用.新兴市场国家应采取应对策略,做好风险识别和预警,加强预期管理,增强货币政策协调和合作,有效防范和化解外溢影响.     

A Global Ex-vessel Fish Price Database: Construction and Applications

Synopsis We describe the first effort at creating a global ex-vessel fish price database, which is required for understanding the economic behavior of participants in the world’s fisheries. We demonstrate potential applications of the database by linking it to a spatially defined catch database, which makes it possible to attach landed values to species in both time and space. This is the first database available publicly where interested members of the public, researchers and managers can easily find and access ex-vessel prices of the world’s major commercial fish species. Preliminary results indicate that the average real price of a number of species have declined between 1950 and 2002. The estimated landed value of fish globally, in year 2000 dollars, was about US$24 billion in 1950. It increased steadily to about US$90 billion in the early 1970s, reached a peak of US$100 billion at the end of the 1980s, and declined to about US$80 billion in 2000. The top 15 fishing countries cumulatively account for 79% of total real landed value, with Japan leading, even though the value of its landings has been declining.      

景区环境控制指标体系研究--以三峡库区为例

根据景区环境控制的原则,本文从生态环境、空间环境、设施环境以及社会环境四个方面建立起三峡库区景区环境控制指标体系,并以重庆库区为例对各项指标的控制标准进行了较为详细的论述.