Validation and forecasting accuracy in models of climate change

Forecasting researchers, with few exceptions, have ignored the current major forecasting controversy: global warming and the role of climate modelling in resolving this challenging topic. In this paper, we take a forecaster’s perspective in reviewing established principles for validating the atmospheric-ocean general circulation models (AOGCMs) used in most climate forecasting, and in particular by the Intergovernmental Panel on Climate Change (IPCC). Such models should reproduce the behaviours characterising key model outputs, such as global and regional temperature changes. We develop various time series models and compare them with forecasts based on one well-established AOGCM from the UK Hadley Centre. Time series models perform strongly, and structural deficiencies in the AOGCM forecasts are identified using encompassing tests. Regional forecasts from various GCMs had even more deficiencies. We conclude that combining standard time series methods with the structure of AOGCMs may result in a higher forecasting accuracy. The methodology described here has implications for improving AOGCMs and for the effectiveness of environmental control policies which are focussed on carbon dioxide emissions alone. Critically, the forecast accuracy in decadal prediction has important consequences for environmental planning, so its improvement through this multiple modelling approach should be a priority.     

鸭绿江河口水文特性对丹东市城市空间格局演变的影响

丹东市是因港而形成和发展的城市,文章收集了不同时期鸭绿江影响航运的水文特性,探讨影响港口布局进而影响丹东市条带状空间格局的内在驱动力。结果表明:城区空间格局演变是不同时期对水文要素的响应:早期的选址是作为鸭绿江防区薄弱环节来设防,此处的鸭绿江水流平缓、沙洲较多、易于涉水;丹东设制和开埠时期,以鸭绿江的对外港口运输,适宜的潮差和流量是丹东城市雏形的重要因素;随着建设东北东部现代化港口城市的定位,原有丹东内港的水深、潮差、河床宽度和泥沙淤积等要求已不能满足这种要求,城市空间形态沿鸭绿江向大东港方向延伸,形成了丹东与东港同城化的极为狭长的条带状城区。     

Environmental Kuznets Curve with Adjusted Net Savings as a Trade‐Off Between Environment and Development

The Environmental Kuznets Curve (EKC) hypothesises that emissions first increase at low stages of development then decrease once a certain threshold has been reached. The EKC concept is usually used with per capita Gross Domestic Product as the explanatory variable. As others, we find mixed evidence, at best, of such a pattern for CO₂ emissions with respect to per capita GDP. We also show that the share of manufacture in GDP and governance/institutions play a significant role in the CO₂ emissions–income relationship. As GDP presents shortcomings in representing income, development in a broad perspective or human well‐being, it is then replaced by the World Bank's Adjusted Net Savings (ANS, also known as Genuine Savings). Using the ANS as an explanatory variable, we show that the EKC is generally empirically supported for CO₂ emissions. We also show that human capital and natural capital are the main drivers of the downward sloping part of the EKC.     

收入不确定性对农民消费的影响研究

不确定性一直是限制农民消费的重要因素,研究和测算不确定性对我国农民消费的影响对于解决农民消费问题具有重要意义。本文通过调整离差率对收入不确定性进行测算,并采取构造消费函数和进行分段比较两种方法对收入不确定性与农民消费之间的作用关系进行实证研究。研究发现:收入不确定性的数值大小及其方向问题都对农民消费具有显著影响。进而,在此基础上,提出促进我国农民消费升级的对策建议。     

借鉴国际经验完善我国财政审计

财政审计是发展我国社会主义市场经济的需要，对加强财政收支管理，增强国力，防止职务腐败等都有重要意义。美国、英国、日本三个主要发达国家的财政审计比较完善，借鉴它们经验，有利于规范和完善我国财政审计，推动市场机制完善和促进经济稳定发展。     

转型经济时期战略变化过程研究--基于主体影响和控制的观点

本文整合并扩展了代理理论、控制理论对于战略变化的研究内容,将主体影响、内部控制和战略变化速度和幅度纳入统一的分析框架,建立了解释不同企业战略变化过程差异的理论模型.文章认为政府、股东、经营者三种利益主体在企业决策中影响力的不同将导致企业选择内部控制方式(财务控制和战略控制)的差异倾向,从而影响到企业战略变化决策的制定和执行,最终会对战略变化速度和幅度产生显著的影响.     

我国证券市场多时间跨度的分形特征研究

我国证券市场具有分形统计特征.在研究中发现:我国股市的趋势周期成分具有长度约为56个月的非周期性循环;季节成分中记忆性可以覆盖约10个月;短期波动成分中记忆性可覆盖3.3个月.     

Bootstrapping R and adjusted R in regression analysis

In this paper, using the bootstrap method, we consider to estimate the standard errors of R² and which are measures of their precision, and to construct their confidence intervals. It is shown by Monte Carlo experiments that the bootstrap standard errors are considerably accurate estimates of the exact ones. It is also shown that although the bootstrap 95% confidence interval of R² do not include the true value of the parent coefficient of determination in some particular cases, such a phenomenon does not occur when is used.     

短期经营决策模型的相关范围及其改进

在“决策会计”的理论体系中,通常将决策划分为短期经营决策和长期投资决策两类。现实经济生活中,短期经营决策涉及的不仅是“短期”的影响因素,通常还会涉及到企业的“长期”影响因素。因此,有关短期经营决策的模型需要加以改进,只有放宽“相关范围”的条件,才能做出准确的判断。本文将重点分析研究中短期经营决策模型的“相关范围”,进一步讨论“相关范围”以外的因素对决策模型的影响,提出短期经营决策的改进思路。