Panel LM unit root tests with level and trend shifts

This paper considers a Lagrange multiplier (LM) based panel unit root test that allows for heterogeneous structural breaks in both the intercepts and slopes of a series. We note that many popular time series variables are likely to exhibit changing means and/or trends over time. Given that the usual tests will depend on the nuisance parameters indicating the locations of the trend breaks, we adopt a transformation procedure that makes our new panel unit root tests invariant to the nuisance parameters. To illustrate the importance of the power gain provided by our test, we examine the convergence hypothesis using relative ratios of per capita health care expenditures in 20 OECD countries. Our results provide evidence that the convergence hypothesis is supported.     

我国商品流通的变迁与发展趋势

计划体制下形成的是与高度集权的经济体制相适应的分配式商品流通组织体系。转轨时期商品流通呈现“三多一少”的格局，流通的低层次性和非系统化。未来的商品流通呈现出弱化二元经济特征、批发业革新、信息化等趋势。     

Evaluation of the social and economic impact of carbon dioxide (CO2) emissions on sustainable mobility using cumulative ordinal models: trend odds model

In the context of environmental sustainability evaluation, grouped under climate change, health and ecosystem themes, an impact that could be investigated is the Global Warming Potential (GWP), whose sources are a multitude. In urban areas the evaluation of real vehicles emissions is an essential activity in order to suggest possible solution to local administrators. They still express the need to improve and maintain the characteristics of the breathing air at the best possible quality level. Moreover, these solutions, such as planning measures or traffic control management in respect of pollution, would be apply at different geographical levels, i.e. national, regional or urban scale. Another factor to be investigated is the effect of technologies and emission control systems to comply more stringent limits (Euro 4/5/6) and improve air quality to a lower environmental impact. GWP, indicator of climate change, is measured in terms of CO₂ equivalency emission values variable. To perform this activity an experimental campaign was carried out with several vehicles from different manufacturers and with a wide variety in terms of mass, power, engine displacement and type approval technology. The experimental plan includes some repetitions of the urban section in Naples city centre.The purpose of this paper is twofold: first, to provide a strategy on the choice of a logistic model with ordinal data and with trend, and, second, to evaluate the usefulness of such models for environmental sustainability (CO₂ and other vehicular pollutant emissions), with particular emphasis on model formulation, the interpretation of model coefficients, and the implications of such models.     

带有结构突变的单位根检验——文献综述

单位根检验是时间序列分析的基础,而是否考虑结构突变对单位根检验的结论有着重要影响,因此,考虑结构突变的单位根检验已成为计量经济学界的一个前沿热点问题。本文回顾了这一问题的发展历史,总结了该领域已取得的一些重要研究成果,最后对该问题最新的发展动向加以概括。     

2000～2018年乡村教师队伍建设研究热点与演化趋势研究

从CNKI数据库收录的2000—2018年文献中,筛选出2148篇"乡村教师队伍建设"领域相关文献,利用CiteSpace和SA-TI3.1软件,对样本文献外部特征、关键词共现、知识演进趋势与热点前沿展开知识图谱分析。首先,展示了乡村教师队伍建设研究现状,梳理了发展动态。其次,划分了"科学发展观""教师教育""特岗教师"和"义务教育管理体制"四大热点研究领域。在此基础上将乡村教师队伍建设研究分为3个演进阶段,并总结出"农村小规模学校""乡村教师专业发展""特岗教师"和"教师流动"四个方向为该领域的前沿热点。最后,分别从公费师范生、基础设施建设和乡村教师的幸福感等方面获得了一些启示。     

Growth and real business cycles in Vietnam and the Asean-5. Does the trend shock matter?

We examine Vietnam’s economy in comparison with its closest trade partners. We show that capital accumulation has been the primary growth engine since the start of its transition to the pro-market economy in 1986 – the Doi Moi. We also show that the cyclical behavior of its macro aggregates is similar to that of its ASEAN-5 peers and other developing countries. We extend the standard small open economy RBC model by considering habit persistence and government consumption, which allows a close match of the moments of the growth variables. At the business cycle frequency, transitory productivity shocks account for approximately one-half of Vietnam’s output variance, while country risk and non-transitory productivity shocks account to close to one-fifth each. Regarding the Solow residual’s volatility, we find that the trend component merely accounts for 12 % of this variance in Vietnam, while in Thailand it is only 6 %. These findings refute the “the cycle is the trend” hypothesis in Aguiar and Gopinath (2007) and align with the hypotheses in García-Cicco et al. (2010) and Rhee (2017), where the stationary component is overwhelmingly dominant. We claim that technological progress and productivity-enhancing measures are fundamental for Vietnam’s economy to sustain high growth.     

Is it one break or ongoing permanent shocks that explains U.S. real GDP?

The relative importance of permanent versus cyclical shocks to GDP has been found to depend on the presence or absence of a single break in mean growth. We estimate unobserved components models conditional on a trend break having occurred in any specified quarter and use the Bayesian model averaging to combine the conditional estimates. We estimate a break occurred around 2006:1. Allowing for a break significantly reduces estimates of trend variance. However, enough spread remains in the posterior distribution to indicate that available data does not definitively settle the question of the relative importance of trend versus cycle.     

Lack of divine coincidence in New Keynesian models

The literature has long agreed that the divine coincidence holds in standard New Keynesian models: the monetary authority is able to simultaneously stabilize inflation and output gap in response to preference and technology shocks. I show that the divine coincidence holds only when inflation is stabilized at exactly zero. Even small deviations from zero generate policy trade-offs. I demonstrate this result using the model׳s non-linear equilibrium conditions to avoid biases from log-linearization. When the model is log-linearized, a non-zero steady state level of inflation gives rise to what I call the endogenous trend inflation cost-push shock in the New -Keynesian Phillips curve.     

我国环境领域技术处于怎样的水平

针对我国环境科技发展现状与重大需求，结合理论梳理，构建了技术评价理论解释模型。在此基础上，采取专家调查方式，重点与美国、日本、德国等主要发达国家进行对比，对环境领域9个子领域技术发展趋势、技术水平和发展阶段进行了评价。结果表明，我国环境领域与国际先进水平的差距正在逐渐缩小，虽有部分技术领先，但大部分还处于跟踪前沿状态，而且原创性技术较少、产业化程度较低，环境科技支撑国家生态文明建设和持续和谐发展任重而道远。     

具有中国特色的证券市场投资者结构缺陷问题研究

我国证券市场经历了近20年的发展,已经日趋完善和成熟,取了很大的成功,并赢得了国际社会的认可和信任。但是由于我国的证券市场相对于发达国家发展了百年的市场来说只能是刚刚起步,在发展的过程中难免会有不足之处。目前我国证券市场最大的问题之一就是投资者结构比例不平衡的问题。