Co‐movements in commodity prices: a note based on network analysis

This article analyses co‐movements in a wide group of commodity prices during the time period 1992–2010. Our methodological approach is based on the correlation matrix and the networks inside. Through this approach we are able to summarize global interaction and interdependence, capturing the existing heterogeneity in the degrees of synchronization between commodity prices. Our results produce two main findings: (a) we do not observe a persistent increase in the degree of co‐movement of the commodity prices in our time sample, however from mid‐2008 to the end of 2009 co‐movements almost doubled when compared with the average correlation; (b) we observe three groups of commodities which have exhibited similar price dynamics (metals, oil and grains, and oilseeds) and which have increased their degree of co‐movement during the sampled period.     

非洲猪瘟疫情对我国肉类价格影响的区域异质性研究

[目的]非洲猪瘟疫情暴发导致猪肉等畜产品市场供需结构性、区域性失衡,进而导致肉类价格大幅波动,不利于畜牧业高质量可持续发展。[方法]文章通过构建覆盖全国30个省（市、区,不含港澳台、西藏）,包括猪牛羊和白条鸡四大肉类价格和非洲猪瘟疫情指数的动态面板数据,运用面板向量自回归模型（PVAR）,研究非洲猪瘟疫情对猪肉等主要肉类价格的冲击和影响在重点、约束、适度发展区和潜力增长区(1)的区域异质性。[结果]（1）非洲猪瘟疫情对不同区域不同肉类价格的影响存在着正负向不趋同的方向性差异,在冲击程度大小和时滞期上均存区域异质性;（2）区域间和区域内不同省份间猪肉等肉类生产流通和供需形势、及非洲猪瘟发生发展程度的差异是非洲猪瘟疫情对这些肉类价格冲击影响异质性产生的主要原因。[结论]非洲猪瘟疫情对肉类价格影响存在较为明显的区域异质性,亟需进一步优化生猪等畜牧产业布局,加快形成区域协同发展格局;健全动物疫病防控体系,建立多方协同联动机制;完善市场风险预警调控机制,加快实现产需顺畅匹配,确保畜产品市场总体平稳运行和畜牧业健康可持续发展。     

北京市房地产价格影响因素分析及限购政策绩效评估

随着经济的高速发展,城市的房价也呈现出急剧攀升的态势,脱离了正常的价格波动轨道,大大增加了城市居民的生活成本。以首都北京为例,房价的上升幅度远远超过预期。在经济理论的基础上,运用近几年北京房地产行业的统计数据建立回归模型,可以对影响北京房价的因素进行分析,并且可以对北京市政府2011年2月出台的＂京八条＂限购政策进行绩效评估。     

Forecasting UK house prices: A time varying coefficient approach

Previous studies of UK house prices, developed from the demand and supply ofhousing or from the asset market approach have been poor in terms of robustness and ex-post forecasting ability. The UK housing market has suffered a number of structural changes, particularly since the early 1980s with substantial house price increases, financial market deregulation and the removal of mortgage market constraints through competition. Consequently, models which assume that the underlying data-generating process is stable and apply constant parameter techniques tend to suffer in terms of parameter instability. This article uses the Time Varying Coefficient (TVC) methodology where the underlying data-generating process in the UK housing market is treated as unstable. The estimation results of the TVC regression of UK house prices is compared with those obtained from three alternative constant parameter regressions. Comparisons of forecasting performance suggest the TVC regression out-performs forecasts from an Error Correction Mechanism (ECM), Vector Autoregressive (VAR) and an Autoregressive Time Series regression.     

Valuing ecosystem goods and services: a new approach using a surrogate market and the combination of a multiple criteria analysis and a Delphi panel to assign weights to the attributes

A new approach to valuing ecosystem goods and services (EGS) is described which incorporates components of the economic theory of value, the theory of valuation (USappraisal), a multi-model multiple criteria analysis (MCA) of ecosystem attributes, and a Delphi panel of experts to assign weights to the attributes. The total value of ecosystem goods and services in the various tenure categories in the Wet Tropics World Heritage Area (WTWHA) in Australia was found to be in the range AUD$188 to $211 million year⁻¹, or AUD$210 to 236 ha⁻¹ year⁻¹ across tenures, as at 30 June 2002. Application of the weightings assigned by the Delphi panelists and assessment of the ecological integrity of the various tenure categories resulted in values being derived for individual ecosystem services in the World Heritage Area. Biodiversity and refugia were the two attributes ranked most highly at AUD$18.6 to $20.9 million year⁻¹ and AUD$16.6 to $18.2 million year⁻¹, respectively.     

Noisy chaotic dynamics in commodity markets

The nonlinear testing and modeling of economic and financial time series has increased substantially in recent years, enabling us to better understand market and price behavior, risk and the formation of expectations. Such tests have also been applied to commodity market behavior, providing evidence of heteroskedasticity, chaos, long memory, cyclicity, etc. The present evaluation of futures price behavior confirms that the resulting price movements can be random, suggesting noisy chaotic behavior. Prices could thus follow a mean process that is dynamic chaotic, coupled with a variance that follows a GARCH process. Our conclusion is that models of this type could be constructed to assist in forecasting prices in the short run but not over long run time periods.First version received: June 2001/Final version received: March 2003     

Wealth and sustainable development: the role of David Pearce

Green net national product was thought to be one way of measuring sustainable income. However, David Pearce understood that a better measure of sustainable development was to look at what a generation is leaving in form of capital assets to later generations. In this article, his arguments and insights are highlighted against recent theoretical advances.     

房价对居民消费的跨空间影响——基于中国278个城市空间面板数据的实证研究

本文首先基于住房财富效应,构建了房价变动对居民消费的跨空间影响的分析框架。该框架阐释了住房财富效应的区域差异:不同地区间房价的空间传导、居民的异地消费以及消费的示范效应,使得本地房价变动可能引起周边地区居民消费的连锁反应。其后,本文利用中国278个地级市2000—2018年数据,通过空间面板杜宾模型,实证考察了不同地区住房财富效应的差异,以及房价变动对居民消费的跨空间影响。结果显示:(1)虽然中国整体上存在住房财富效应,但西部城市财富效应并不显著,并且核心城市还存在负财富效应。(2)不同城市间房价对消费存在跨区影响。东部城市和核心城市对周边城市消费的正向影响很显著,而边缘城市则对周边城市消费有显著的负向影响。(3)不同城市间的消费也具有空间上的示范效应。最后,本文从房价和居民消费空间联动的视角,为政府扩大内需、调控房地产市场提供了相关政策建议。     

An innovation to improve health outcomes in Amajuba district,KwaZulu-Natal,South Africa

Systems’ thinking places high value on understanding the context. This study focused on the collection of disaggregated data in order to understand the context, to facilitate improvement of health outcomes. The aim of this article was to assess the implementation of municipal ward-based health data collection (disaggregated data) and health care workers’ perceptions of this data collection process. This cross-sectional study used mixed methods in Amajuba district. The participants were professional nurses at the Primary Health Care level. Of the 131 respondents, 123 (93.9%) collected municipal ward-based health data, and found it useful. Opportunities for improving data collection were identified. Disaggregation of the data at ward level contributes to a better understanding of the target population’s health, assists planning for health needs and enables provision of targeted interventions in order to improve health outcomes, to prevent financial regression and waste of health resources.