In addition to being a moral cataclysm of horrific proportions, Donald Trump’s plan to round up and deport all undocumented immigrants in the United States could reduce annual output from the private sector anywhere from 2.9 percent to 4.7 percent, a study has found.

According to government statistics, there are more than 11 million undocumented immigrants in the U.S., and approximately 6.8 million of them are employed. The study, conducted by the American Action Forum, a conservative think tank, found that deporting them would reduce private sector output by anywhere from $381.5 billion to $623.2 billion. From Reuters:

The American Action Forum analysis used data from the Bureau of Labor Statistics to estimate the value of the output from undocumented immigrants. It also concluded that there would not likely be enough legal employees in these sectors to fill the vacancies that would result from mass deportations.

The study did not factor in potential impacts of mass deportations on consumption, investment and other economic factors, the group said.

The U.S. economy is projected to produce some $18.7 trillion worth of goods and services in 2016, according to the International Monetary Fund. A loss of $400 billion in output would amount to about 2 percent of that figure.

The hospitality industry would be particularly impacted, Politico notes, as undocumented workers make up 9 percent of its labor force.

Trump’s plan would also necessitate systemic, brutal human rights violations. But hey—money talks.