Preventing HIV in injection drug users: exploring the tradeoffs between interventions

Injection drug users (IDUs) transmit the human immunodeficiency virus (HIV) via both needle sharing and sex. Available interventions for this population have varying costs and effectiveness and focus on different risk behaviors. In this analysis, we look at two interventions. One is inexpensive, broad-based and provides modest risk reductions (street outreach (SO)); the other is narrowly focused, expensive and relatively effective (methadone maintenance). This analysis explores the effects of population risk behavior, intervention effectiveness, intervention costs, and decision constraints when allocating funds between these two interventions to maximize effectiveness. We develop a model of the spread of HIV, dividing IDUs into susceptibles (uninfected) and infectives, and separately portraying sex and injection risk. We simulate the epidemic in New York City for time periods from the mid-1980s to the early 1990s, and incorporate the behavioral effects of two interventions performed singly or in combination to find the allocation that maximizes the number of infections averted in the IDUs and their noninjecting sex partners, assuming interventions have increasing marginal costs. We find that the optimal allocation nearly always involves spending the maximum allowable amount on SO. This result is largely insensitive to variations in risk parameters, intervention efficacy, or cost. The model's structure, however, makes clear that many factors contribute to this insensitivity, namely the scope of the interventions, the dual drug/sex nature of HIV risk in the population, the asymmetry of sexual risk for men and women, and the potential benefits to nonIDUs.     

广西北部湾经济区发展战略探析

分析了广西北部湾经济区的发展现状,创造性地提出其发展要因,最后,基于发展要因提出经济区发展战略,以供决策参考。     

人力资本与经济增长关系研究——教育投资对经济增长的贡献自上市公司的经验证据

知识经济时代经济增长所依靠的已不仅是货币资本,更重要的是人力资本,货币资本的获得和财富的积累都是由人力资本推动的。人力资本是现代经济增长与发展的源泉和动力,增加人力资本投资,提高人力资源质量,已成为促进经济发展的重要手段。从我国经济增长的影响因素看,人力资本作为生产要素对经济增长具有决定作用,人力资本投资对我国经济增长具有战略意义。本文对经济增长理论及人力资本理论进行了介绍,并运用实证分析方法探讨了教育投资对经济增长的贡献。     

Factor taxation and labor supply in a dynamic one-sector growth model

This paper studies a class of AK-type growth models with factor income taxes, public capital stock and labor–leisure trade offs. While a higher capital tax rate reduces economic growth in the short run, the long-term growth effect is ambiguous and remains ambiguous even if the level of tax rate is larger than the degree of government externality. A higher labor income tax rate has ambiguous growth effects both in the short and long runs. However, if the intertemporal elasticity of substitution for labor supply is sufficiently small, a higher labor tax rate always lowers economic growth in the long run, despite the existence of productive government taxation.     

基于循环经济的环境财务分析指标体系构建

目前我国的经济增长与自然环境之间的矛盾十分突出,需要大力发展循环经济,而建立环境财务分析指标体系,有助于推动企业循环经济的发展。本文介绍了循环经济的基本理论,简要回顾了国内外关于循环经济的理论研究成果。在此基础上,分析了循环经济对传统财务分析指标的影响,主要体现在主体多元化、目标多元化和指标多样化上。并根据3R原则设计了若干环境财务分析指标,指出了这些指标在沃尔评分法中的应用。     

中国城市住宅市场的结构差异性分析

市场价商品房、经济适用住房和廉租房构成了目前中国城市住宅市场的供应体系.依据中国30个主要城市的房地产开发统计数据,选择吸纳率作为评价住宅市场供需均衡状态的指标,利用固定影响变截距模型,重点研究了商品房和经济适用住房供给结构的城市差异性.研究发现,在城市住宅市场中,经济适用住房市场和商品房市场具有很强的相关性.作为具有政府资助性质的经济适用住房建设,存在典型的地域性特征,其政策的设定和实施会对整个住宅市场产生影响,地方政府应在利用比较全面的住宅市场指标体系进行综合分析基础上,制定适合本地的经济适用住房政策.     

西部民族地区新农村建设中的特色经济与特色人力资源开发研究

西部民族地区新农村建设,特色经济仍然是其必然选择,而特色经济的发展,特色人力资源的开发是有效途径.在西部民族地区农村人力资源开发中,存在着重视程度不够、开发基础薄弱、开发机制不健全以及开发主体单一等问题.鉴于此,从政府作用机制、教育机制以及人才管理机制等方面对西部民族地区新农村建设中特色人力资源开发的有效途径进行探讨.     

利率风险与债务期限结构的正反馈效应分析

本文在总结以前学者有关债务期限结构分析的基础上,提出了债务期限结构与利率波动之间可能存在正反馈机制。通过对经筛选的我国上市企业面板数据的实证分析,发现银行间同业拆借利率可以较好地反映企业债务期限结构的变化。而分行业的实证分析则表明,利率波动加剧会使绝大多数行业的短期债务比例降低,呈现显著负相关关系。但现阶段我国的利率形成受企业债务期限结构变化的影响不明显,长短期的面板Granger因果检验无法通过。最后,本文从利率风险及利率期限结构的角度对我国上市公司特殊的债务结构给出了新的解释。     

How do economic policy uncertainty and geopolitical risk drive Bitcoin volatility?

We investigate how economic policy uncertainty (EPU) and geopolitical risks (GPR) impact Bitcoin volatility with respect to factors related to type and nationality of uncertainty, investigated period, relationship horizon and extreme conditions. Applying ARDL model and quantile regression for monthly data from August 2010 to September 2021, we reveal that June 2014 corresponds to a key date that marks a reversal in the investigated relationship. Furthermore, we show that the relationship between uncertainty and bitcoin volatility changes according to different factors. US uncertainty has short run effects on Bitcoin volatility, while China’s uncertainty has rather long run effects. Moreover, Bitcoin volatility responds in the same manner to US EPU and GPR, while, it responds differently to China's EPU and GPR. In extreme quantiles, we find that Bitcoin hedges against US EPU and GPR. Further, Bitcoin hedges against either individual or joint effects of US uncertainty, but not both.     

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.