Economic Models as Analogies
解释了经济学家为何分析假设不真实的模型，并提出这些模型作为“理论案例”，通过类比帮助理解经济问题，而非提供一般规则。
People often wonder why economists analyze models whose as- sumptions are known to be false, while economists feel that they learn a great deal from such exercises. We suggest that part of the knowledge generated by academic economists is case-based rather than rule-based. That is, instead of oering general rules or theories that should be contrasted with data, economists often analyze models that are \theoretical cases", which help understand economic problems by drawing analogies between the model and the problem. According to this view, economic models, empirical data, experimental results and other sources of knowledge are all on equal footing, that is, they all provide cases to which a given problem can be compared. We of- fer complexity arguments that explain why case-based reasoning may sometimes be the method of choice and why economists prefer simple cases.