Harvard economist George Borjas, who is fairly critical of immigration, wrote yesterday that he has concluded that most male illegal aliens come to the United States to work. He reports on the results of a study he did in which he teased out data from the Pew Research Center and the Current Population Survey. He writes:
This paper provides a comprehensive empirical study of the labor supply behavior of undocumented immigrants in the United States. Using newly developed methods that attempt to identify undocumented status for foreign-born persons sampled in the Current Population Surveys, the empirical analysis documents a number of findings, including the fact that the work propensity of undocumented men is much larger than that of other groups in the population; that this gap has grown over the past two decades; and that the labor supply elasticity of undocumented men is very close to zero, suggesting that their labor supply is almost perfectly inelastic.
Take a look at his graphs in the link. Specifically, of men aged 20 to 65:
. 74% of native Americans (people native to America) were employed.
. 81% of legal immigrants were employed.
. 85% of illegal aliens were employed.