Instantaneous Gratification *
提出了一个即时满足模型，该模型比现有模型更广泛地适用于完全市场和不完全市场，能解决动态不一致模型中的多重均衡问题，并同时具备单一福利标准和过度消费的行为倾向。
Extending Barro (1999) and Luttmer & Mariotti (2003), we introduce a new model of time preferences: the instantaneous-gratification model. This model applies tractably to a much wider range of settings than existing models. It applies to both complete- and incomplete-market settings and it works with generic utility functions. It works in settings with linear policy rules and in settings in which equilibrium cannot be supported by linear rules. The instantaneous-gratification model also generates a unique equilibrium, even in infinite-horizon applications, thereby resolving the multiplicity problem hitherto associated with dynamically inconsistent models. Finally, it simultaneously features a single welfare criterion and a behavioral tendency towards overconsumption