I don't think we can fully measure the impact, though it appears more negative than positive:
http://www.cbo.gov/ftpdocs/87xx/doc8711/12-6-Immigration.pdf
...
This is what I worry about, though, since I work for a significant amount of time with lower income urban communities:
Immigration and African-American Employment Opportunities: The Response of Wages, Employment, and Incarceration to Labor Supply Shocks
As long as Americans are still struggling (and they are), I don't really believe we should be allowing illegal immigration to increase their challenges. These impacts are also felt by native Hispanics, Native Americans, poor whites, and others. The economic impact of illegal immigration is the greatest on the poorest Americans.
I don't think anyone here necessarily denies that illegal immigrants pose a burden to legal citizens in some instances. In fact, I'll openly say that they in many circumstances, their use of social services exceeds their tax payments.
But there are two factors to consider here. The first is one which only fellow consequentialists and utilitarians will likely care about, and which deontologists will likely scorn, which is the degree of the suffering caused to illegal immigrants through forcible deportation or border closing compared to the suffering caused to American taxpayers through the imposition of higher fees and taxes through the presence of illegal immigrants. I firmly believe that the suffering caused to illegal immigrants by forced residence in an inhumane and utterly destitute environment is more severe than that caused to American taxpayers through the imposition of higher taxes upon them. So, that's approaching the issue from a purely ethical perspective.
From a more "practical" perspective, we need to differentiate between causation and correlation as well as between cause and effect when it comes to analyzing the social and economic costs of illegal immigrants' presence in the U.S.
I believe a case can be made that the problems incurred by illegal immigration can be remedied by amnesty and the granting of legal status to illegal immigrants. Consider this:
Undocumented Immigrants in Georgia: Tax Contribution and Fiscal Concerns
The question lawmakers attempt to answer is: Do undocumented immigrants pay enough in taxes to cover the services used? For undocumented immigrants, the answer is unclear. However, for legal immigrants, studies have shown that first generation immigrants pay more in federal taxes than they receive in federal benefits. The same does not hold true for state taxes and services, however, as first generation immigrants often use more in services than they pay in taxes. However, the descendants of the first-generation immigrant correct that pattern and contribute more in taxes at both the federal and state level than they consume in services at both levels. Each generation successively contributes a greater share due to increased wages, language skills, and education.
I don't believe that those "increased wages, language skills, and education" can be obtained by immigrants while they retain an illegal status, as this places them into a disenfranchised segment of the population. The wages are probably the most obvious example of this.
While retaining an illegal status, immigrants are forced to either obtain low paying positions in the informal economy, (lawn mowing, house cleaning, etc.), or the lesser option that far fewer take of using fake social security numbers to obtain employment in the formal economy. In the former case, illegal immigrants' tax payments don't sufficiently cover their use of social services because of their low wages. In the latter case, immigrants' tax payments may cover their use of social services, but they are forced to commit a crime to obtain adequate employment. (It's also notable that in the latter case, immigrants do not reap the benefits of Social Security because of the fact that they use fake numbers, in which case the benefits will either go to the person who actually owns that number, or their payments will simply remain in federal coffers should no one have that number. So they're really only hurting themselves in that regard.)
Should illegal immigrants be granted amnesty, they would be able to unionize and demand higher salaries and benefits, at which point they could pay a corresponding amount of taxes.
Yep, and if I wanted to live there I'd emigrate LEGALLY after I brushed up on my Spanish.
I'm not sure where the idea that most Latin American immigrants were sullenly unwilling to learn English and demand that American communities promote Spanish came from. 92% of the Hispanic population believe that it's important for immigrants to learn English, while only 87% of whites and 83% of blacks believe the same. (
www.pewhispanic.org/files/factsheets/20.pdf)