If people do not want to borrow, monetary policy, although not impotent,(中文意思)

这是2010年9月2号英国《经济学人》杂志上的一句话。
If people do not want to borrow, monetary policy, although not impotent, gives a smaller lift to the economy than it normally would.
翻译：如果人们不想借贷，货币政策即使很有效，对经济的拉升作用也不会有通常那么大。
Monetary policy gives a smaller lift to the economy than it normally would是句子主干，although not impotent（尽管不是无效）是插入语。
我想，楼主到了阅读这种层次材料的程度，应该一点即通吧？