Agricultural Policy Simulation Based on Computable General Equilibrium Model

[Objective] This study aimed to examine the simulated effect of Computable General Equilibrium （CGE）-based agricultural policy simulation system. [Method] The policy simulation platform based on CGE model was constructed by integrating policy simulation, CGE model and Decision Supporting System （DSS）. The scenario analysis method was used to analyze the agricultural subsides policy simulation through empirical analysis. [Result] Farmers were the main beneficiaries of increasing agricultural production subsidies, which increased farmers＇ income and improved the export of agriculture products. The prototype system could solve the problems in actual policy simulation. [Conclusion] The results lay the foundation for the quantitative study on agricultural subsidy policy in China.

Intensity Allocation Criteria of Carbon Emissions Permits and Regional Economic Development in China——Based on a 30-Province/Autonomous Region Computable General Equilibrium Model

The intensity allocation criteria of carbon emissions permits and its influence on China＇s regional development are analyzed through the 30-province/autonomous region computable general equilibrium （CGE） model. Simulation results show that： industrial intensity criteria without taking regional economic development into account deepen the unbalance of regional economic development; regional intensity criteria without taking industrial properties into account exert little negative impact on regional harmonious development, but relatively high negative influence on high-carbon emission industries. The two-step allocation scheme that the central government allocates emissions permits to provincial governments based on regional economic development and then provincial governments allocate emissions permits to emission resources or entities based on industrial properties is a feasible and operable choice.

Comparision of China's volatile organic compound pollution management:a computable general equilibrium approach

The public health and ecological impacts of volatile organic compound(VOCs) pollution have become a serious problem in China,arousing increasing attention to emissions control.In this context,this paper analyses the effectiveness of VOC reduction policies,namely pollution charges and environmental taxes at the national and industrial sector levels.It uses a computable general equilibrium model,which connects macroeconomic variables with VOC emissions inventory,to simulate the effects of policy scenarios(with 2007 as the reference year).This paper shows that VOC emissions are reduced by 2.2% when a pollution charge equal to the average cost of engineering reduction methods-the traditional approach to regulation in China-is applied.In order to achieve a similar reduction,an 8.9% indirect tax would have to be imposed.It concludes that an environmental tax should be the preferred method of VOC regulation due to its smaller footprint on the macroeconomy.Other policies,such as subsidies,should be used as supplements.

An AI Embedded Object-Oriented Approach for Formulating Computable General Equilibrium

This paper proposes and illustrates an AI embedded object-oriented methodology to formulate the computable general equilibrium (CGE) models. In this framework, a CGE model is viewed as a collection of objects embedded AI or namely agents in computer world, corresponding to economic agents and entities in real world, such as government, households, markets and so on. A frame representation of major objects in CGE model is used for trade and environment. Embedded Al object-oriented approach (or software agent) is used in the CGE model representation can able to narrow the gap among the semantic representation, formal CGE (mathematical) representation and computer and algorithm representation, and to improve CGE in understanding and maintenance etc. In such a system, constructing a CGE model to appear an intuitive process rather than an abstract process. This intuitive process needs more understanding of the substance of economics and the logic underlying the problem rather than mathematical notation.

Impacts of Total Energy Consumption Control and Energy Quota Allocation on China′s Regional Economy Based on A 30-region Computable General Equilibrium Analysis

This paper examined the impacts of the total energy consumption control policy and energy quota allocation plans on China′s regional economy. This research analyzed the influences of different energy quota allocation plans with various weights of equity and efficiency, using a dynamic computable general equilibrium(CGE) model for 30 province-level administrative regions. The results show that the efficiency-first allocation plan costs the least but widens regional income gap, whereas the outcomes of equity-first allocation plan and intensity target-based allocation plan are similar and are both opposite to the efficiency-first allocation plan′ outcome. The plan featuring a balance between efficiency and equity is more feasible, which can bring regional economic losses evenly and prevent massive interregional migration of energy-related industries. Furthermore, the effects of possible induced energy technology improvements in different energy quota allocation plans were studied. Induced energy technology improvements can add more feasibility to all allocation plans under the total energy consumption control policy. In the long term, if the policy of the total energy consumption control continues and more market-based tools are implemented to allocate energy quotas, the positive consequences of induced energy technology improvements will become much more obvious.

Will Coal Price Fluctuations Affect Renewable Energy Substitution and Carbon Emission? A Computable General Equilibrium-Based Study of China

Changes in the energy price system will determine the direction of evolution of the energy industry structure.As a country where coal is the dominant energy source,what is the effect of coal price fluctuations on China’s industry development costs and energy consumption structure?To investigate this problem,this paper utilized an economy–energy–environment computable general equilibrium model.In this study,four aspects were analyzed:Energy supply side,proportion of renewable energy consumption,macroeconomy,and changes in CO_(2) emissions.The results of this study show that an increase of 10%–20%in coal prices contributes to a shift into using renewable energy,which leads to energy saving and emission reduction.Renewable energy and clean energy rose by 0.57%–4.47%in the energy structure,but this has a certain negative impact on the macroeconomy.The gross domestic product(GDP)fell by 0.07%–0.18%.As a result,the decline in coal prices became an obstacle to renewable energy substitution and energy conservation.In addition,we put forward policy suggestions according to the results in energy,economic,and environmental effects.

The Impact of Climate Change on Agriculture Production in Ethiopia: Application of a Dynamic Computable General Equilibrium Model

The challenge of meeting the ever-increasing food demand for the growing population will be further exacerbated by climate change in Ethiopia. This paper presents the simulated economy-wide impacts of climate change on the agriculture sector of Ethiopia using a dynamic computable general equilibrium (CGE) model. The study simulated the scenarios of agricultural productivity change induced by climate change up to the year 2050. At national level, the simulation results suggest that crop production will be adversely affected during the coming four decades and the severity will increase over the time period. Production of teff, maize and sorghum will decline by 25.4, 21.8 and 25.2 percent, respectively by 2050 compared to the base period. Climate change will also cause losses of 31.1 percent agricultural GDP at factor cost by 2050. Climate change affects more the income and consumption of poor rural households than urban rural non-farming households. The reduction in agricultural production will not be evenly distributed across agro ecological zones, and will not all be negative. Among rural residents, climate change impacts tend to hurt the income of the poor more in drought prone regions. Income from labor, land and livestock in moisture sufficient highland cereal-based will decline by 5.1, 8.8 and 15.2 percent in 2050. This study indicated that since climate change is an inevitable phenomenon, the country should start mainstreaming adaptation measures to sustain the overall performance of the economy.

A General Equilibrium Model for Energy Policy Evaluation Using GTAP-E for Vietnam

In the past several years, there has been growing concern on the scarcity of energy resources, the volatility of energy prices, and the impact of energy sector on climate change. In this context, energy-environment models designed for analysis of energy systems have become more important. In this paper, a Computable General Equilibrium Model （CGE） using an energy-environmental version of Global Trade Analysis Project （GTAP） model （known as GTAP-E） for Vietnam is presented based on the GTAP Data Base version 7. The model is developed following the original structure and the revised version of the GTAP-E model. This model is used to simulate the adoption of carbon tax for Vietnam for the base year of 2004. The economy-level and detailed sector-specific effects are also examined considering energy intensive and non-intensive sectors. Simulation results show the negative influences of different carbon tax scenarios to Vietnam＇s economy. The results would also indicate the potential of carbon taxation as a driving force for the mitigation of carbon dioxide and for new and renewable energy promotion in Vietnam. In fact, this study is the first simulation exercise of energy-environmental policy for the Vietnamese case.

Socio-economic and energy-environmental impacts of technological change on China's agricultural development under the carbon neutrality strategy

Promoting agricultural modernisation through technological change is an important strategy for China.China's carbon neutrality strategy is leading to systemic socio-economic changes that could exacerbate the uncertainty of agricultural development.Therefore,applying a computable general equilibrium(CGE)model,this study characterises the agricultural sector in detail,introducing endogenous technological change proxied by research and development(R&D)to assess the impact of different technological change scenarios on agricultural development under the carbon neutrality target.The results show that allocating carbon revenue for R&D inputs can mitigate the significant negative impact of achieving carbon neutrality on knowledge capital and production in agricultural sectors.Overall,using carbon revenue only for R&D input in crop sectors has the optimal effect on increasing the agricultural sectors'knowledge capital,improving crop production and profit,reducing crop external dependence and promoting the synergistic reduction of carbon and pollutant emissions.However,this scenario has the largest negative impact on macro-economics and household welfare.In contrast,allocating carbon revenue to promote technological change in broader non-energy sectors or both crops and non-energy sectors can effectively mitigate negative socio-economic impacts,but the positive impact on agricultural development is minimal.These findings provide practical insights for the rational use of carbon revenue to expand agricultural R&D investment and ensure balanced agricultural and economic development under the carbon neutrality target.

Dynamics Analysis of Close-coupling Multiple Helicopters System

The particularity and practicality of harmony operations of close-coupling multiple helicopters indicate that the researches on it are urgent and necessary, Using the model that describes two hovering helicopters carrying one heavy load, an inertia coordinate system and body coordinate systems of each sub-system are established. A nonlinear force model is established too. The equilibrium computation results can be regarded as the reference control inputs of the flight control system under hovering or low-speed flight condition. After the establishment of a translation kinematics model and a posture kinematics model, a coupling dynamics model of the multiple helicopter system is set up. The results can also be regarded as the base to analyze stabilization and design a controller for a close-coupling multiple helicopters harmony operation system.

CGE Simulation for Levying Carbon Tax in China and International Experience of Levying Carbon Tax

Levying carbon tax is conducive to reducing carbon dioxide emissions and protecting the environment.The author firstly reviewed some relevant empirical studies on carbon tax both home and abroad,and then established the CGE model and simulated levying carbon tax in China.The study found that levying carbon tax would have little impact on China's economy:in a short-term,China's GDP might decrease by 0.51%,while in a long-term it might decrease by 0.08%;however,the carbon dioxide emissions would be substantially reduced.Meanwhile,levying carbon tax has some negative impact on the output of each industry in the very economic structure;of this,the mineral extractive industries would be influenced the most.Then the author summarized experience of levying carbon tax in foreign countries.

The Impact of Climate Change on China＇s Grain Market and Food Security-- A CGE Model Approach

This paper examines the impact of climate change on China＇s grain production and food security. The research is one of the four studies on future conditions of China＇s food production system under the influence of climate change using numerical simulation methods, carried out under a national 973 project entitled ＂impacts of climate change on food systems in China and its adaptation＂. The other three studies focus on changes in cultivated land area and food production, while this study incorporates their grain yield results into a general equilibrium model to simulate future conditions of the grain market. Our simulation analysis arrives at the impact of climate change by comparing such economic variables as grain production, consumption, and GDP growth rate between a baseline scenario and two climate change scenarios. Our results are summarized as follows： （1） In 2050, the total grain production will reach 689.683 million tons--584.264 million tons of total grain consumption and 42.808 million tons of exports. Without considering losses and inventory demand, in 2050 China＇s grain supply and demand will remain well balanced, with a slight surplus expected. （2） Climate change is expected to benefit China＇s macro economy and individual sectors. In comparison with the baseline scenario of no climate change, real wage, real GDP, investment, household consumption, exports, and other macroeconomic indicators will rise under the climate change scenarios. As far as the agricultural, manufacturing, and service sectors are concerned, production, consumption, imports, and exports will each be favorably affected by climate change. （3） The favorable impact of climate change on China＇s macroeconomy and individual sectors under the high emissions scenario （A2） is stronger than that under the low emissions scenario （B2）. （4） In the grain market, climate change is expected to increase supply, reduce imports, increase supply, and demand; and supply will increase more than demand does. All in all, if taking into the fertilization effect of CO2 account, climate change is expected to strengthen China＇s grain supply and safeguard food security.

Evaluating the Economic and Environmental Impacts of a Global GMO Ban

The objective of this research is to assess the global economic and greenhouse gas emission impacts of banning GMO crops. This is done by modeling two counterfac-tual scenarios and evaluating them apart and in combination using a well-know Computable General Equilibrium (CGE) model, GTAP-BIO. The first scenario models the impact of a global GMO ban. The second scenario models the impact of increased GMO penetration. The focus is on the price and welfare impacts, and land use change greenhouse gas (GHG) emissions associated with GMO technologies. Much of the prior work on the economic impacts of GMO technology has relied on a combination of partial equilibrium analysis and econometric techniques. However, CGE model-ling is a way of analyzing economy-wide impacts that take into account the linkages in the global economy. Here the goal is to contribute to the literature on the benefits of GMO technology by estimating the impacts on price, supply and welfare. Food price impacts range from an increase of 0.27% to 2.2%, depending on the region. Total welfare losses associated with loss of GMO technology total up to $9.75 bil-lion. The loss of GMO traits as an intensification technology has not only economic impacts, but also environmental ones. The full environmental analysis of GMO is not undertaken here. Rather we model the land use change owing to the loss of GMO traits and calculate the associated increase in GHG emissions. We predict a substan-tial increase in GHG emissions if GMO technology is banned.

Assessing the Regional Economic Ripple Effect of Flood Disasters Based on a Spatial Computable General Equilibrium Model Considering Traffic Disruptions

With growing regional economic integration,transportation systems have become critical to regional development and economic vitality but vulnerable to disasters.However,the regional economic ripple effect of a disaster is difficult to quantify accurately,especially considering the cumulated influence of traffic disruptions.This study explored integrating transportation system analysis with economic modeling to capture the regional economic ripple effect.A state-of-the-art spatial computable general equilibrium model is leveraged to simulate the operation of the economic system,and the marginal rate of transport cost is introduced to reflect traffic network damage post-disaster.The model is applied to the 50-year return period flood in2020 in Hubei Province,China.The results show the following.First,when traffic disruption costs are considered,the total output loss of non-affected areas is 1.81 times than before,and non-negligible losses reach relatively remote zones of the country,such as the Northwest Comprehensive Economic Zone(36%of total ripple effects).Second,traffic disruptions have a significant hindering effect on regional trade activities,especially in the regional intermediate input—about three times more than before.The industries most sensitive to traffic disruptions were transportation,storage,and postal service(5 times),and processing and assembly manufacturing(4.4 times).Third,the longer the distance,the stronger traffic disruptions'impact on interregional intermediate inputs.Thus,increasing investment in transportation infrastructure significantly contributes to mitigating disaster ripple effects and accelerating the process of industrial recovery in affected areas.

Simulated Scenarios for China＇s Economic Growth： 2011-2030

Considering domestic and international impact on economic growth, this paper adopts a computable general equilibrium （CGE） model to simulate three scenarios for China＇s economic growth. Results indicate that during the 12^th Five-year Plan period （2011：2015）, China＇s economic growth is expected to reach 8 per cent and enjoy great potential for rapid growth in the mid- and long-term run. Future economic growth is mainly confronted by the risk of unbalanced economic development and growing resources and environmental pressures. Whether this potential is in transforming its development pattern. tapped depends on China＇s achievements

Could the EU carbon border adjustment mechanism promote climate mitigation?An economy-wide analysis

Due to concerns about carbon leakage and sectoral competitiveness,the European Union(EU)proposed implementing the carbon border adjustment mechanism(CBAM).The effectiveness and potential negative consequences of CBAM have aroused extensive discussion.From the perspective of the economy-wide analysis,this study uses a global computable general equilibrium model to explore the rationality of CBAM from the aspects of socioeconomic impact and the effects of promoting climate mitigation.Furthermore,the potential alternative mechanism of CBAM is proposed.The results show that CBAM can reduce the EU's gross domestic product(GDP)loss;however,the GDP loss in all other regions increases.Moreover,CBAM raises household welfare losses in most regions,including the EU.Second,although CBAM can reduce the marginal abatement cost in eight regions,it comes at the cost of greater economic losses.Furthermore,the economic and household welfare cost of raising emissions reduction targets in regions like the USA and Japan is substantially higher than the impact of passively accepting the CBAM;therefore,CBAM's ability to drive ambitious emission reduction initiatives may be limited.Finally,for the potential alternative mechanism,from the perspective of reducing economic cost and household welfare losses,the EU could implement domestic tax cuts in the short-term and promote global unified carbon pricing in the long-term.

Applying Earth Observation Technologies to Economic Consequence Modeling:A Case Study of COVID‑19 in Los Angeles County,California

Earth observation(EO) technologies,such as very high-resolution optical satellite data available from Maxar,can enhance economic consequence modeling of disasters by capturing the fine-grained and real-time behavioral responses of businesses and the public.We investigated this unique approach to economic consequence modeling to determine whether crowd-sourced interpretations of EO data can be used to illuminate key economic behavioral responses that could be used for computable general equilibrium modeling of supply chain repercussions and resilience effects.We applied our methodology to the COVID-19 pandemic experience in Los Angeles County,California as a case study.We also proposed a dynamic adjustment approach to account for the changing character of EO through longer-term disasters in the economic modeling context.We found that despite limitations,EO data can increase sectoral and temporal resolution,which leads to significant differences from other data sources in terms of direct and total impact results.The findings from this analytical approach have important implications for economic consequence modeling of disasters,as well as providing useful information to policymakers and emergency managers,whose goal is to reduce disaster costs and to improve economic resilience.

An equilibrium analysis of the land use structure in the Yunnan Province, China

Global land use structure is changing rapidly due to unceasing population growth and accelerated urbanization, which leads to fierce competition between the rigid demand for built-up area and the protection of cultivated land, forest, and grassland. It has been a great challenge to realize the sustainable development of land resources. Based on a computable general equilibrium model of land use change with a social accounting matrix dataset, this study implemented an equilibrium analysis of the land use structure in the Yunnan Province during the period of 2008-2020 under three scenarios, the baseline scenario, low TFP （total factor productivity） scenario, and high TFP scenario. The results indicated that under all three scenarios, area of cultivated land declined signifi- cantly along with a remarkable expansion of built-up area, while areas of forest, grassland, and unused land increased slightly. The growth rate of TFP had first negative and then positive effects on the expansion of built-up area and decline of cultivated land as it increased. Moreover, the simulated changes of both cultivated land and built-up area were the biggest under the low TFP scenario, and far exceeded the limit in the Overall Plan for Land Utilization in the Yunnan Province in 2020. The scenario-based simulation results are of important reference value for policy-makers in making land use decisions, balancing the fierce competition between the protection of cultivated land and the increasing demand for built-up area, and guaranteeing food security, ecological security, and the sustainable development of land resources.

Computation of Fisher–Gale Equilibrium by Auction

We study the Fisher model of a competitive market from the algorithmic perspective.For that,the related convex optimization problem due to Gale and Eisenberg(Ann Math Stat 30(1):165–168,1959)is used.The latter problem is known to yield a Fisher equilibrium under some structural assumptions on consumers’utilities,e.g.,homogeneity of degree 1,homotheticity.Our goal is to examine applicability of the convex optimization framework by departing from these traditional assumptions.We just assume the concavity of consumers’utility functions.For this case,we suggest a novel concept of Fisher–Gale equilibrium by using consumers’utility prices.The prices of utility transfer the utility of consumption bundle to a common numéraire.We develop a subgradient-type algorithm from Convex Analysis to compute a Fisher–Gale equilibrium via Gale’s approach.In order to decentralize prices,we additionally implement the auction design,i.e.,consumers settle and update their individual prices and producers sell at the highest offer price.Our price adjustment is based on a tatonnement procedure,i.e.,the prices change proportionally to consumers’individual excess supplies.Historical averages of consumption are shown to clear the market of goods.Our algorithm is justified by a global rate of convergence.In the worst case,the number of price updates needed to achieve anε-tolerance is proportional to 1/ε^(2).

Exploring U.S.-China climate cooperation through linked carbon markets

Emissions trading systems(ETSs)are a widely used policy tool for driving emissions reductions and serve as an avenue for international climate cooperation.Following the recent global agreement on carbon market standards at COP26,this study explores linked ETSs as an avenue for the U.S.and China to cooperate on climate action.The emissions,energy,and economic effects of linked ETSs are analyzed through the China-in-Global Energy Model(C-GEM),a multi-regional,computable general equilibrium model.Assuming the development of national economy-wide ETSs,two scenarios are developed linking China and the U.S.:1)a bilateral U.S.-China ETS linkage 2)a multilateral ETS linkage that includes China,the U.S.,and nations in Southeast Asia.Results indicate that emissions and energy consumption outcomes would be similar in the bilateral and multilateral scenarios.However,economic outcomes are more favorable in the multilateral linkage scenario.When China and the U.S.engage in bilateral ETS linkage,China predominantly benefits from additional support for domestic decarbonization while the U.S.benefits from increased GDP compared to without ETS linkage.Adding Southeast Asia to establish multilateral linkage improves GDP outcomes for all participants,reducing adverse effects on China's GDP while boosting GDP for the U.S.and Southeast Asia.For policymakers considering the design and implementation of international ETSs,this study presents updated modeling on the effects of ETS linkage on each country as well as the economic benefits of expanding participation to additional regions.