Reading helps they say - reading through Steffan's blog I came across this report from UC Berkeley School of Information about the role of immigrants in the US economy. The findings are not a surprise but the scale of the 'immigrant economy' is tremendous:

- Nationwide, these immigrant-founded companies produced $52 billion in sales and employed 450,000 workers in 2005.

- Indians have founded more engineering and technology companies in the US in the past decade than immigrants from the U.K., China, Taiwan and Japan combined. Of all immigrant-founded companies, 26% have Indian founders.

- Almost 80% of immigrant-founded companies in the US were within just two industry fields: software and innovation/manufacturing-related services.

- Immigrants were least likely to start companies in the defense/aerospace and environmental industries. They were most highly represented as founders in the semiconductor, computer, communications, and software fields.

- The trend has been dramatic; according to our estimates the contribution of non-citizen immigrants to these international patent applications increased from 7.3% in 1998 to 24.2% in 2006.

- Over half (52.4%) of Silicon Valley startups had one or more immigrants as a key founder, compared with the California average of 38.8%.

No stats in the report about tax contributions but they should not lack behind :)