There are only so many ways in which a country can grow its economy: by increasing the amount of capital invested, adding more workers, making more-productive use of its financial and human resources, or by a combination of these factors.

It’s crucially important to keep this in mind now that Donald Trump has reclaimed the presidency, because his announced plans to initiate a massive expulsion of immigrants will impact America’s financial future—and, likely, yours as well.

Is the American economy becoming more productive? Since 2005 U.S. productivity has grown by an average of 1.4% per year—half the rate of growth of the 1995-2005 period and of the 1950s and 1960s.

What about capital? Private-sector investment has yet to return to its pre-2005 level. As a percentage of gross domestic product (GDP), U.S. investment, according to the World Bank, has been consistently below the world average since 1993, except, briefly, between 1997 and 2001.

What about the labor force? Is it getting bigger? If we count only native-born workers, the answer is no. But the workforce isn’t shrinking, data from the U.S. Bureau of Labor Statistics shows. That’s because the number of foreign-born workers has increased by 3.55 million in the last five years.

And, yes, “undocumented” individuals comprise a significant portion of the foreign-born pool of workers—as many as 8.3 million overall, according to the Center for Migration Studies, or 5.2 percent of the total U.S. workforce. Among the major U.S. industries that depend on them are construction (1.5 million), food services (more than 1 million) and agriculture and landscaping (more than 600,000).

In a modern economy it is entirely normal to partly rely on newcomers; that’s how an interconnected world and a globalized market work.

In fact, the U.S. economy has relied on newcomers for centuries. Historically, between 13 and 14 percent of the U.S. workforce has been made up of people who were born elsewhere. The percentage today is a bit higher (about 17 percent), but, given how much more integrated the world’s economies are, the proportion is actually smaller than one would expect—certainly smaller than the fierce, widespread anti-immigrant backlash we have witnessed recently would suggest.

The numbers, of course, have to do with supply and demand: in this case of labor.

What are the concerns? One is the perception that a disproportionate number of undocumented immigrants are violent criminals. By all means, U.S. authorities should prosecute foreign-born offenders and expel those who commit violent crimes. But research does not indicate that foreigners are more prone to committing violent crimes than native-born Americans.

So, perhaps the new administration should pause before it embarks on its expulsion program and make sure: 1) that it has its facts straight on immigrants and crime, and 2) that its actions won’t cause more harm than good—especially as they impact the economy.

Let’s be clear. The incoming administration’s immigration plans do not appear to be uniformly bad. The administration does appear to be considering such sensible measures as significantly expanding the H1B visa program, which allows U.S. companies to hire foreign-born workers with college degrees (or the equivalent) to fill specialized jobs in science, math, medicine and other fields. This will allow foreign-born students who graduate from U.S. universities to stay and work here for up to six years, and possibly longer.

Whoever has been thinking along these lines also should be considering other measures that could help align supply with demand in the labor market. The “immigration problem” that has consumed Americans for so many years probably wouldn’t exist if the United States had a flexible, open-minded, realistic guest worker program that includes the substantial number of low-skilled workers the economy needs. That’s how you would judge how many undocumented folks should be allowed to work in the U.S. How many do we need?

Such a program would help sustain the economy and get rid of, or drastically reduce, the so-called immigration crisis. For all of its bluster, perhaps the Trump administration will be the one to permanently solve this problem.