Once beliefs and expectations are introduced into economics, as is surely reasonable, the results of fiscal policy become indeterminate. Too much depends on what people think the results of the policy will be.
这就是宏观经济学给自己造成的混乱局面的一部分。信念和预期被引入经济学后（这看起来相当合理），财政政策的结果就变得含糊不清了。太多结论取决于人们认为政策结果会是如何。用经济学的行话说，政策结果是“模型依赖的”。