Here is a study which estimates that that immigrants are responsible for 32% of aggregate U.S. innovation, with more than half of that effect coming from spillovers to U.S.-born collaborators.

Stanford Business School researchers, using patent records, identified likely immigrants and patenting from 1990 to 2016. They found that immigrants made up about 16% of U.S.-based inventors but produced 23% of patents, 24% of citation-adjusted patents, and 25% patent economic value.

Why the contribution is so large

This can be explained not be brilliance but by demographics. Immigrant inventors are especially productive in the middle of their careers, when inventive output typically peaks. The share of foreign born residents with post graduate degrees is about the same as U.S. citizens (about 15%) but as I have noted before they tend to arrive in a concentration of prime working age (25- 45).

They also appear more likely to work in fast-moving technology sectors and in major innovation hubs. Immigrant inventors are more connected to global knowledge flows. They rely more on foreign technologies, collaborate more often with foreign inventors, and are cited more often abroad.

The authors claim is that immigrants raise the productivity of collaborators. Using premature deaths of inventors as a natural experiment, the authors find that when an immigrant inventor dies, the decline in co-inventors’ productivity is larger than when a U.S.-born inventor dies.

 

Source: The Contribution of High-Skilled Immigrants to Innovation in the United States