Arguing against immigration policies that force foreign-born innovators to leave the United States, a new study to be released on Tuesday shows that immigrants played a role in more than three out of four patents at the nation’s top research universities.

Conducted by the Partnership for a New American Economy, a nonprofit group co-founded by Mayor Michael Bloomberg of New York, the study notes that nearly all the patents were in science, technology, engineering and math, the so-called STEM fields that are a crucial driver of job growth.

The report points out that while many of the world’s top foreign-born innovators are trained at United States universities, after graduation they face “daunting or insurmountable immigration hurdles that force them to leave and bring their talents elsewhere.”

The Partnership for a New American Economy released a paper in May saying that other nations were aggressively courting highly skilled citizens who had settled in the United States, urging them to return to their home countries. The partnership supports legislation that would make it easier for foreign-born STEM graduates and entrepreneurs to stay in the United States.