Experience tell us that individuals and private corporations tend to act in their own short-term economic and political interest,
最后一个词interest,在这句话里应该是利益的意思吧，如何不加s，当利益讲不是可数吗？难不成是兴趣的意思，我感觉不太合理啊
这是一种省略现象。economic andpolitical interest = economic （interest) and political interest.
