Data-based mechanistic modelling and forecasting globally averaged surface temperature

The main objective of this paper it to model the dynamic relationship between global averaged measures of Total Radiative Forcing (RTF) and surface temperature, measured by the Global Temperature Anomaly (GTA), and then use this model to forecast the GTA. The analysis utilizes the Data-Based Mechanistic (DBM) approach to the modelling and forecasting where, in this application, the unobserved component model includes a novel hybrid Box-Jenkins stochastic model in which the relationship between RTF and GTA is based on a continuous time transfer function (differential equation) model. This model then provides the basis for short term, inter-annual to decadal, forecasting of the GTA, using a transfer function form of the Kalman Filter, which produces a good prediction of the ‘pause’ or ‘levelling’ in the temperature rise over the period 2000 to 2011. This derives in part from the effects of a quasi-periodic component that is modelled and forecast by a Dynamic Harmonic Regression (DHR) relationship and is shown to be correlated with the Atlantic Multidecadal Oscillation (AMO) index.     

An Examination of the Interaction Between Modelling and Its Relationship with Construction Kits: Lessons from the Past and for the Future

Construction kits have played a significant part in nurturing the growth and development of the minds and manipulation-based skills of children (and adults) in formal and non-formal education settings. These kits have origins rooted in the representation of the built world and now have a diversity of form and function, including technical versions with moving parts. This article examines some of the historically based ideas that lie behind the role that kits may have in terms of physical modelling. The article traces the transformation of kits from simple bricks and blocks into more complicated pieces for space-filling and achieving the transfer of forces and motion. This transformation occurred during the Victorian era when the influence of the ideas of educationalists and, perhaps rather strangely, exponents of early aviation, played major roles in determining the diversity of forms of construction kit and modelled possibilities that are now to be seen in classrooms and homes. The article ends with a review of some of the lessons from the past and present that will need to be considered in relation to concrete modelling in schools for the future. This revised version was published online in July 2006 with corrections to the Cover Date.     

Crossing spatial analyses and livestock economics to understand deforestation processes in the Brazilian Amazon: the case of São Félix do Xingú in South Pará

The Amazon is the largest tropical forest area on Earth, and has been undergoing rapid deforestation for the last four decades. In the Brazilian Amazon, large‐scale pasture for cattle ranching and soybean production are the main land uses, leading to a yearly deforestation rate of 0.5%. These conversions are mostly located in frontier areas distributed along the so‐called “arc of deforestation”. Within this large zone, various land use change processes are interacting through several modes of land valuation and organisation. From several case studies in the State of Pará (Brazil), the current project aims at analysing how landscape dynamics are related to infrastructure development, ecological conditions, zoning policies and to the evolution and the organisation of the production, consumption and marketing chains of livestock products. This paper presents the results for one test site, the region of São Félix do Xingú, South of Pará This region is the focus of land speculation, cattle expansion, and deforestation. Road construction, investments in electrical energy, financial credit for cattle, and the land reform policies have all fuelled this process. All these factors make this region one of the most dynamic agricultural frontiers in the Brazilian Amazon. The main objective of the paper is to improve our understanding of deforestation processes by crossing spatial analyses and 1ivestock economics.studies, and to characterise the role and impact of various natural and anthropic factors in the location and development of the main types of farmers, and their policy implications.     

Learning in Design and Technology: The Impact of Social and Cultural Influences on Modelling

The paper introduces the highly problematic nature of modelling in design and technology education and examines the relationship between cognitive and concrete modelling. Its aim is to gain insight into what learners do, rather than what others say they ought to do in their learning activities. The variety of purposes that educators have for learners’ modelling are discussed through examining the contested curriculum justification for design and technology education itself. The paper proposes that learners’ modelling cannot be extracted from the social milieu in which they act and it provides some insights of these social influences through the analysis of two case studies. Their settings are a girls’ secondary school and a college of higher education. Each case study is presented independently but organised with a common format to consider a) the impact of assessment on learning intentions and outcomes; b) cultural influences on learning and modelling; c) social influences on learning and modelling. A discussion of the emergent themes considers implications for teachers. This revised version was published online in July 2006 with corrections to the Cover Date.     

Extending working hours: why not work 42 h rather than 38?—a CGE analysis for Germany

Faced with a record level of unemployment, the present debate in Germany is to extend the weekly hours of work. In this paper the employment effects of an economy-wide increase in weekly hours are quantified on the basis of a computable general equilibrium model for different specifications of the wage setting rule and the use of additional policy-induced public income. The simulation results back the argument of the opponents of longer working time that not more jobs will be created. However, when the higher tax revenues from GDP growth are used to reduce social security contributions, then the claim of the proponents that more jobs will be created can be supported.     

A New Approach to Random Utility Modeling using the Dirichlet Multinomial Distribution

In this paper we introduce a new econometricapproach to analyzing recreational site choicedata, the Dirichlet multinomial model. Thismodel, which nests the standard conditionalmultinomial logit model, can accommodateover-dispersed data and may provide moreefficient estimators of coefficients andconsequent welfare measures than the standardconditional logit model, which is so widelyused in the Random Utility Model approach torecreation demand. We illustrate thisDirichlet approach using a data set of rockclimbers in Scotland, and study the impacts onper-trip consumers surplus of alternativemanagement strategies for popular rock climbingsites. Results show that the Dirichletmultinomial approach produces coefficient andwelfare estimates having smaller samplingvariability in this case. We also compareclassical welfare measures with their posteriorequivalents, which allow for welfare changes tobe dis-aggregated.     

A note on the ecological-economic modelling of marine reserves in fisheries

This paper gives an overview of the bioeconomic modelling of marine reserves, and illustrates how economists have responded to the modelling results found in the ecological literature. The economic analysis is shown to be far more pessimistic with regards to the potential of marine reserves as a fisheries management tool, than what one finds in the purely ecological analysis, the reason being the latter's neglect of issues such as discounting and economic incentive behaviour. However, economic analysis, despite some of it being relatively advanced with regards to spatiality, is still simplistic with regards to for instance ecosystem and habitat content. A simple expansion of the existing bioeconomic models with regards to positive habitat effects of area closures is presented and analysed, showing room for improved results from marine reserve implementation as compared to the existing analysis.     

论货币供应量作为我国货币政策中介目标的有效性

本文把理论分析与实证分析相结合,运用协整检验、VEC模型和方差分解方法分析了1996年以来我国货币供应量、物价和产出的季度时间序列,论证了货币供应量与物价、产出间具有较强的相关性。从货币供应量的构成分析,基础货币具有较强的可控性;货币乘数可控性较差,但对货币乘数可以利用ARMA模型进行较为准确的预测。由此,本文得出的结论是货币供应量具有较强的可控性,从而有理由认为,货币供应量作为我国货币政策的中介目标在现阶段仍然是有效的。     

Inflation model of a semicommand economy

A semicommand economy can be defined as a system where the pricing of goods is influenced by the market but where the prices of production factors are under control of the state. The model presents various pricing and economic policy measures to deal with inflation. It is constructed as a dynamic supply-side focused, input-output model which differentiates nominal and real movements. It examines the possible responses of prices and the volume of production to certain measures or programmes to counteract inflation. The cases described are based on the present day Yugoslav economy.     

Does Increased Extraction of Natural Gas Reduce Carbon Emissions?

Without an international climate agreement, extraction of more natural gas could reduce emissions of CO₂ as more clean natural gas may drive out dirty coal and oil. Using a computable equilibrium model for the Western European electricity and natural gas markets, we examine whether increased extraction of natural gas in Norway reduces global emissions of CO₂. We find that both in the short run and in the long run total emissions are reduced if the additional quantity of natural gas is used in gas power production in Norway. If instead the additional quantity is exported directly, total emissions increase both in the short run and in the long run. However, if modest CO₂-taxes are imposed, increased extraction of natural gas will reduce CO₂ emissions also when the additional natural gas is exported directed.earlier version of this paper was presented at the 25th Annual IAEE International Conference in Aberdeen June 2002.