As U.S. lawmakers and policy wonks continue to wrestle with questions of immigration reform, a new report from the Pew Research Center shows a decline in the number of unauthorized immigrant workers in construction. The report, titled "Share of Unauthorized Immigrant Workers in Production, Construction Jobs Falls Since 2007," looks at the unauthorized immigrant labor force and changes as a result of the recession.

Overall, the size of the unauthorized immigrant labor force has not changed dramatically (5.1% of the nation’s labor force in 2012), but authors Jeffrey S. Passel, senior demographer, D’Vera Cohn, senior writer, and Molly Rohal, communications manager, note changes in the kinds of jobs workers hold. While a large majority (88%) work in low-skill blue collar and farming jobs, more unauthorized workers are in white collar positions.

The number of unauthorized immigrants in management or professional related jobs grew by 180,000, while the number in construction or production jobs fell by about 475,000, mirroring rises and declines in the overall U.S. economy. The share of all unauthorized immigrant workers with management and professional jobs grew to 13% in 2012 from 10% in 2007, and the share with construction or production jobs declined to 29% from 34%.

In construction specifically:

the number of unauthorized immigrants declined from 1.6 million in 2007 to 1.2 million in 2012 (a 23% decline), a period in which total U.S. construction employment fell to from 9.9 million to 8.5 million (a 15% decline). Unauthorized immigrants rose from 5% of all construction workers in 1995 to 9% in 2000 before peaking at 16% in 2007 and 2008. The share bumped downward to 14% in 2012.

Today, by law, employers must check the status of all new hires. One option is E-Verify, a program through U.S. Citizenship & Immigration Services. It's optional, but some states and federal project contracts require it.

One option for legally hiring non-citizens in skilled positions is the popular H-1B visa program. The Pew Report was released just as the H-1B application period opened April 1. The program is capped at 85,000 and if number of applications submitted during the first week of April exceeds the cap, as it has in recent years, visas are awarded in a lottery.