Undocmented workers only hurt other undocumented workers new research says

In "The Labor Market Experience and Impact of Undocumented Workers" by
JULIE L. HOTCHKISS and MYRIAM QUISPE-AGNOLI....

The authors find that a greater share of undocumented workers in an industry has a statistically significant negative impact on the wages of documented workers. In addition, undocumented workers have significantly lower labor supply elasticity, likely as a result of their limited employment and grievance opportunities. Furthermore, the inflow of undocumented workers does more to displace earlier hired undocumented workers than it does to displace documented workers.


This paper differs from of undocument worker studies, like Steward, Raub and Elliott (2007), that use survey data like the Mexican Migration Project (MMP), in the way in which
unauthorized individuals are identified. The paper uses State for GA administrative data to identify invalid social security numbers used by employers. The downside is that the their is little person level data so wage penalty equations are ran at the industry level.

See: http://papers.ssrn.com/sol3/papers.cfm?abstract_id=1109169