Donald Trump’s plan of deporting all illegal immigrants in the United States would hurt the country’s economy immensely, according to a new report.

Approximately 6.8 million of the 11.3 million illegal immigrants in the U.S. are employed, a report by the conservative think tank American Action Forum found. By rounding up and deporting these individuals, even temporarily, the country’s economic private industry output would decrease between $381.5 billion and $623.2 billion.