发表机构
Aix-Marseille School of Economics; Institut Universitaire de France; Prairie View A&M University; Houston Baptist University; Lund University（艾克斯-马赛经济学院; 法国高等研究院; 普雷里维尤农工大学; 休斯顿浸会大学; 隆德大学）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本研究在Ramsey增长模型中引入Forster式不可逆污染，发现最优减排虽改变但未消除不可逆阈值，并揭示出耦合生态曲率与社会贴现率的混合不可逆条件，界定可持续性边界。
AI 中文摘要
我们研究了一个具有不可逆污染的Ramsey经济中的最优增长问题，其中自然吸收能力是非单调且非凹的，遵循Forster的设定。在缺乏污染控制的情况下，资本动态与污染脱钩，我们刻画了一个关于最大吸收能力的简单阈值：当吸收能力高于该阈值时，最优路径是可持续的；低于该阈值时，不可逆污染的最优状态开始出现。随后，我们引入最优减排污染控制，以评估不可逆污染是否不再是最优的。我们推导出一个关于资本、消费、污染和污染（影子）成本的四维动力系统，并辅以最优减排的代数规则，该系统最终降为三维，其中减排线性地进入污染动态。我们的主要结果是，最优减排改变了不可逆性阈值，但并未消除它。更重要的是，我们表明将Forster的污染动态嵌入Ramsey增长模型会产生一种新的混合生态不可逆性条件，这种条件在仅考虑污染的框架中是看不见的。该条件将生态系统曲率与社会贴现率耦合，在结构上具有稳健性，并且优于所有可受政策干预的可行性条件，它定义了可持续性可实现的世界与不可实现的世界之间的边界。
英文摘要
We study optimal growth in a Ramsey economy with irreversible pollution, where the natural absorption capacity is non-monotonic and non-concave a la Forster. In the absence of pollution control, the capital dynamics decouple from pollution, and we characterize a simple threshold on the maximal absorption capacity above which the optimal path is sustainable and below which an optimal regime of irreversible pollution sets in. We then introduce an optimal abatement pollution control to assess whether irreversible pollution ceases to be optimal. We derive a four-dimensional dynamical system for capital, consumption, pollution and the (shadow) cost of pollution, coupled with an algebraic rule for optimal abatement, which is eventually reduced to dimension three, with abatement linearly entering the pollution dynamics. Our main result is that optimal abatement shifts the irreversibility threshold but does not eliminate it. More importantly, we show that embedding the Forster's pollution dynamics into a Ramsey growth model generates a novel hybrid ecological irreversibility condition that is invisible in pollution-only frameworks. Coupling ecosystem curvature with the social discount rate, it is structurally robust and preeminent over all feasibility conditions amenable to policy intervention and defines the boundary between a world where sustainability is achievable and one where it is not.
Comments30 pages, 2 figures
