For Pennsylvania, the Biden administration’s proposal to create a legal pathway for millions of undocumented people would mean more than lots of new citizens — it would mean more money in state coffers.

Undocumented residents now pay about $135 million a year in state and local taxes. But granting them citizenship would boost that figure by 38%, more than $51 million, according to a new study.

That’s because having citizenship would allow migrants to secure better-paying jobs. And more would file income-tax returns. Both those factors would boost state income as undocumented immigrants left behind informal, off-the-books economies. Who might fill those vacated, unofficial jobs was not addressed.

Those are among the findings in “The Economic Contributions of Pennsylvania’s Immigrants,” by Muhammad Maisum Murtaza, a research associate at the Keystone Research Center. The report also did not address who might fill off-the-books jobs.

The center, which works to produce practical recommendations for a better Pennsylvania, was assisted in the study by immigration-advocacy groups CASA, Make the Road Pennsylvania, and the Pennsylvania Immigration and Citizenship Coalition, and drew on research and expertise from the New York Policy Institute and the Migration Policy Institute in Washington.

It’s far from certain that Congress will approve a route to citizenship for the estimated 11 million undocumented immigrants in this country. Even if it does, the path would not be easy or quick, with the Biden administration proposing at least eight years and multiple background checks between an application for temporary legal status and full U.S. citizenship.

The study looked at where immigrants have come from, how much they pay in different kinds of taxes, and the factors that could increase that tax revenue.

Pennsylvania is home to about 893,000 immigrants, roughly 7% of the state population. More than half are naturalized citizens, and others have various forms of legal status. About 157,000 are undocumented, and about 50,000 of those residents live in Philadelphia.

They came to Pennsylvania from all over the world -- 41% born in Asia, 31% in Latin America, 18% in Europe, and 9% in Africa. Among undocumented migrants, 60% come from Mexico, Central America, and Asia. More than two-thirds have lived in the United States for at least five years.

They’ve faced particular difficulties during the pandemic.

“The hardships experienced in 2020 have exposed the inadequate pay and lack of support our frontline workers receive,” the study said, noting that those workers are likely to be women, people of color, immigrants, or all three.

Immigrants represent 8% of the state workforce, but 9% of its frontline industries. And that figure goes up depending on the industry. For instance, immigrants make up almost 19% of building-cleaning employees and 13% of agricultural workers.

In many cases, immigrants pay taxes into programs that benefit others but from which they themselves are excluded. That includes the federal stimulus checks that helped keep many families afloat during the pandemic. And undocumented workers can’t get unemployment payments.

Overall, immigrants in Pennsylvania paid $10 billion in taxes in 2019, including $6.6 billion in federal and $3.3 billion in state levies, the study found.

About 20% of college-educated, immigrant adults ages 25 and up are either underemployed or have skills that are underutilized, the study said. That’s compared to 16% of all U.S. college-educated adults .

“Immigrants’ current contributions to our state are significant,” the study said, but the chance to tap those unused skills creates “a great potential for growth at very little cost.”