中文摘要
我们分析了在存在时间不一致的政策框架中具有复杂动态的均衡的存在性。我们考虑这样一个经济体：在每一期，执政的政策制定者决定一种耐用公共品（或公共劣品）的水平，该公共品在各政策期之间形成策略性关联。当决策过程具有时间一致性时——例如由仁慈的社会规划者在每一期设定政策——经济展现出唯一均衡，其中状态收敛于一个确定性稳态。当决策者身份随时间以概率方式变化（如政治均衡中那样）时，决策过程便具有时间不一致性。在此情形下，我们识别出周期超过两期的循环均衡与混沌动态得以出现的条件。取决于经济的基本参数，这些均衡可能产生遍历分布，其中状态变量或者持续越过规划者的稳态，或者围绕其波动。混沌行为的程度受时间不一致程度的影响：随着时间不一致程度趋近于零，遍历分布支撑集的大小也收敛于零。
Abstract
We analyze the existence of equilibria with complex dynamics in a policy framework with time inconsistency. We consider an economy where, in each period, the policy maker in power determines the level of a durable public good (or bad) that creates strategic linkages across policy periods. When the decision‐making process is time consistent—such as when a benevolent planner sets policy in every period—the economy exhibits a unique equilibrium where the state converges to a deterministic steady state. When the identity of the decision maker changes probabilistically over time as in a political equilibrium, the decision‐making process becomes time inconsistent. In this scenario, we identify conditions under which equilibria with cycles of more than two periods and chaotic dynamics can emerge. Depending on the economy's fundamental parameters, these equilibria may produce ergodic distributions in which the state variable either persistently overshoots the planner's steady state or fluctuates around it. The extent of chaotic behavior is influenced by the degree of time inconsistency: as the degree of time inconsistency approaches zero, the size of the support of the ergodic distribution converges to zero as well.