Roads to remote and beautiful mountains foster eco-tourism but do not help carry merchandise to the nearest port. A lab built to certify that beef does not have foot-and-mouth disease is of little use in verifying that fruit and vegetable exports are similarly disease-free.
问题在于这些公共提供投入品中有一些只能用于特定的部门或产品。通往偏远而美丽的山区的公路能提振生态旅游，但无助于将货物运往最近的港口。用于检测牛肉是否含有口蹄疫的实验室对于检验水果和蔬菜出口疫病没有任何用处。