MR. KEYNES AND THE ENVIRONMENT: TROPICAL DEFORESTATION AND THE CONCEPT OF USER COST

ABSTRACT Keynes’ General Theory has been a major source of inspiration in almost all areas of economics. However, it has been largely ignored in the environmental economics debate, characterized by a complete dominance of orthodox, neoclassical models. This is the case of tropical deforestation: the existing models that analyze the economic motivations that fuel the land clearing process use unrealistic assumptions and optimal control models that provide misleading results andincorrect policy recommendations. The objective of this paper is to present an alternative perspective for the problem, based on Keynes’ definition of income and user cost. A simple theoretical model is used to describe the importance of land speculation in the capital component, thus affecting the land clearing decision. Economic policies have an important influence in this process, and consistent public policies aiming at controlling deforestation should consider these effects as well as the conventional issues that are addressed by environmental regulators.摘要：凯恩斯的《就业、利息和货币通论》（General Theory）几乎是所有经济学分支领域的重要理论灵感来源。然而，在环境经济学相关讨论中，这一理论却长期被忽视——当前的环境经济学讨论完全由正统新古典主义模型主导。热带森林砍伐议题便是典型例证：现有用于分析驱动土地清理行为的经济动因的模型，往往采用脱离现实的假设，且借助最优控制模型（optimal control models）开展分析，所得结果具有误导性，所提出的政策建议也存在错误。本文旨在基于凯恩斯对收入与使用者成本（user cost）的定义，为该问题提供一种替代性分析视角。本文采用一个简化的理论模型，阐释土地投机在资本构成中的重要性，及其对土地清理决策的影响。经济政策对该过程具有显著影响，因此旨在管控森林砍伐的连贯公共政策，不仅需要考量上述影响因素，还应涵盖环境监管机构通常关注的各类传统议题。