部份原因是这种研究花费时间太长。
Part of the reason is that this kind of research takes a very long time.
缺点是这些政策的决定者是政客，经济消沉时他们要达成正确政策花费时间太长，同时也不愿意在繁荣的时候加税。
The drawback is that it leaves decisions to politicians, who risk taking too long to agree on the right policies in a slump and are unwilling to raise taxes in a boom.
缺点是这些政策的决定者是政客，经济消沉时他们要达成正确政策花费时间太长，同时也不愿意在繁荣的时候加税。
The drawback is that it leaves decisions to politicians, who risk taking too long to agree on the right policies in a slump and are unwilling to raise taxes in a boom.
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