美国国内的工资水平存在着巨大差异。例如，东南部制造业工人的工资比西海岸地区同行的工资低20%。要素价格均等

化理论为什么不能用来解释上述现象？这个例子和美国与墨西哥工资率的差异有何不同？(墨西哥在地理上与美国的东南部和西海岸地区都非常接近，其距离比东南部到西海岸要近。)

There is substantial inequality of wage levels between regions within the United States．For example，wages of manufacturing workers in equivalent jobs are about 20 percent lower in the Southeast than they are in the Far West．Which of the explanations of failure of factor price equalization might．account for this？ How is this case different from the divergence of wages between the United States and Mexico(which is geographically closer to both the U.S. Southeast．and the Far West than the South-east and Far West are to each other)？