Accounting for the gains and losses of ecological assets holds scientific significance in sustaining human well-being.Based on related research on ecological assets,we established a county-scale ecological asset accou...Accounting for the gains and losses of ecological assets holds scientific significance in sustaining human well-being.Based on related research on ecological assets,we established a county-scale ecological asset accounting technology system by analyzing the temporal and spatial variations of county-level ecological assets in China from 1990 to 2018 and clarified the factors which caused the gains and losses of ecological assets.On these bases,optimization and promotion pathways were proposed.The results show that the number of counties dominated by farmland and forest ecological resources accounted for about 45%and 37%of the total counties,respectively.From 1990 to 2018,the quality of county-level ecological stock assets showed an increasing trend,while the water conservation volume decreased in nearly 70%of the counties.The number of counties with the gains(47%)and losses(37%)of ecological flow assets demonstrated spatial patterns which showed the same segmentation characteristics as the“Hu Huanyong Line”,that is,the counties in the vastness of northwest China experienced significant gains,while decreases were widespread in eastern and southern China.The change of ecological assets in more than 70%of the counties was driven by climate change and human activities.The average degree of impact of human activities driving the ecological asset gains in counties was about 80%,while that of climate change causing the ecological asset losses was about 60%.According to various ecological resource types,gain and loss status,and its driving factors,counties in China can be classified into five types:climate change mitigation,climate change adaptation,ecological resources restoration,ecological resources protection,and ecological resources management.Our results indicate that differentiated optimization and promotion pathways can be adopted to achieve desired ecological asset gains.展开更多
In this paper we formulate a continuous-time behavioral (4 la cumulative prospect theory) portfolio selection model where the losses are constrained by a pre-specified upper bound. Economically the model is motivate...In this paper we formulate a continuous-time behavioral (4 la cumulative prospect theory) portfolio selection model where the losses are constrained by a pre-specified upper bound. Economically the model is motivated by the previously proved fact that the losses Occurring in a bad state of the world can be catastrophic for an unconstrained model. Mathematically solving the model boils down to solving a concave Choquet minimization problem with an additional upper bound. We derive the optimal solution explicitly for such a loss control model. The optimal terminal wealth profile is in general characterized by three pieces: the agent has gains in the good states of the world, gets a moderate, endogenously constant loss in the intermediate states, and suffers the maximal loss (which is the given bound for losses) in the bad states. Examples are given to illustrate the general results.展开更多
基金The Strategic Priority Research Program of the Chinese Academy of Sciences,No.XDA23020202。
文摘Accounting for the gains and losses of ecological assets holds scientific significance in sustaining human well-being.Based on related research on ecological assets,we established a county-scale ecological asset accounting technology system by analyzing the temporal and spatial variations of county-level ecological assets in China from 1990 to 2018 and clarified the factors which caused the gains and losses of ecological assets.On these bases,optimization and promotion pathways were proposed.The results show that the number of counties dominated by farmland and forest ecological resources accounted for about 45%and 37%of the total counties,respectively.From 1990 to 2018,the quality of county-level ecological stock assets showed an increasing trend,while the water conservation volume decreased in nearly 70%of the counties.The number of counties with the gains(47%)and losses(37%)of ecological flow assets demonstrated spatial patterns which showed the same segmentation characteristics as the“Hu Huanyong Line”,that is,the counties in the vastness of northwest China experienced significant gains,while decreases were widespread in eastern and southern China.The change of ecological assets in more than 70%of the counties was driven by climate change and human activities.The average degree of impact of human activities driving the ecological asset gains in counties was about 80%,while that of climate change causing the ecological asset losses was about 60%.According to various ecological resource types,gain and loss status,and its driving factors,counties in China can be classified into five types:climate change mitigation,climate change adaptation,ecological resources restoration,ecological resources protection,and ecological resources management.Our results indicate that differentiated optimization and promotion pathways can be adopted to achieve desired ecological asset gains.
文摘In this paper we formulate a continuous-time behavioral (4 la cumulative prospect theory) portfolio selection model where the losses are constrained by a pre-specified upper bound. Economically the model is motivated by the previously proved fact that the losses Occurring in a bad state of the world can be catastrophic for an unconstrained model. Mathematically solving the model boils down to solving a concave Choquet minimization problem with an additional upper bound. We derive the optimal solution explicitly for such a loss control model. The optimal terminal wealth profile is in general characterized by three pieces: the agent has gains in the good states of the world, gets a moderate, endogenously constant loss in the intermediate states, and suffers the maximal loss (which is the given bound for losses) in the bad states. Examples are given to illustrate the general results.