U.S. resource endowments and trade, 1980

U.S. Share of world output:	28.6%
Resource	U.S. share of world resource endowment	Endowment share >,< output share?
R&D scientists	50.7%	___
Physical capital	33.6%	___
Arable land	29.3%	___
Skilled labor	27.7%	___
Semi-skilled labor	19.1%	___
Unskilled labor	0.2%	___

	Specialization rank	Revealed comparative advantage index
Fresh food	102	1.52
Non-electronic machinery	14	1.38
Electronic components	15	1.33
Miscellaneous manufacturing	19	1.31
Transport equipment	20	1.22
Chemicals	19	1.18
Wood products	59	0.93
IT & Consumer electronics	22	0.92
Processed food	110	0.75
Basic manufactures	79	0.63
Textiles	67	0.61
Minerals	113	0.35
Clothing	105	0.23

Source: UNCTAD/WTO. International Trade Center
<http://www.intracen.org/menus/countries.htm>
The "Revealed comparative advantage index" measures the country's revealed comparative advantage in exports according to the Balassa formula. The index compares the share of a given sector in national exports with the share of this sector in world exports. Values above 1 indicate that the country is specialized in the sector under review.
The "Specialization rank" is the ranking of the specialization indices across countries: Rank 1 indicates that the country has the highest specialization index in the world for the sector under review.