但知道是一回事，对行为有没有影响是另外一回事。
他说：“有些媒体在说，中国开发了水电，上游开发水电对下游国家有没有影响啊？”生态环境会不会遭到破坏？
He says there have been media reports that China's upstream hydropower development is having a negative impact on downstream countries, especially environmentally.
这些影响仍然远远小于近期的粮食价格上涨，但它们究竟对穷人有没有影响，如果有是对穷人有益呢还是有害？
These effects are still much smaller than recent food-price spikes, but would they, on balance, help or hurt the poor?
应用推荐