Which of the following statements about transportation costs are correct? Check all that apply. In the United States, the decline in the relative cost of international transportation has made imports more competitive in U.S. markets. International transportation costs decline only in the United States. The global economy has become much less transport intensive than it once was. Since the 1960s, transportation costs have been rising everywhere in the world. World output has shifted into goods whose value is unrelated to their size and weight, and thus less transportation is required for every dollar's worth of exports or imports