Do these numbers indicate that the United States has more trade barriers than, say,
the United Kingdom or Belgium? No. The main factors behind these differences are geography
and size. Distance from other markets explains a part of the lower Japanese ratio.
Size also matters: The smaller the country, the more it must specialize in producing
and exporting only a few products and rely on imports for the other products. Belgium
can hardly afford to produce the range of goods produced by the United States, a country
roughly 40 times its economic size.