The CDI rewards immigration of unskilled people more than skilled. One indicator used in the index is the gross inflow of migrants from developing countries in a recent year, including unskilled and skilled immigrants but leaving out illegals. Another is the net increase in the number of unskilled immigrant residents from developing countries during the 1990s. The index also uses indicators of openness to students from poor countries and aid for refugees and asylum seekers.
Austria and Switzerland tie for first in "importing" the most labor for their size, especially unskilled labor. At the bottom is Japan, whose population of unskilled workers from developing countries actually shrank during the 1990s. The United States, the great nation of immigrants, scores a surprisingly mediocre 4.7. Why? Its inflow of legal immigrants is small for its size and in fact dropped by a third in 2003 as a result of tighter policies since the September 11, 2001, attacks.