Final answer:
The effect of changing import and export mixes in the report is inconclusive.
Step-by-step explanation:
The statement about the effect of changing import and export mixes in the report is most likely inconclusive. The report mentions that imports have typically exceeded exports in the United States, leading to a trade deficit. However, it also states that foreign trade can have powerful effects on specific industries and workers. Without further information on the specific import and export mixes mentioned in the report, it is not possible to determine the exact effect. Therefore, the statement is inconclusive.