If sluggish global growth isn't enough to pump the brakes on a swift-moving U.S. labor market, deporting the undocumented workers certainly would.  That's the conclusion of fresh research from the American Action Forum, a Washington-based conservative policy group that tested Republican presidential frontrunner Donald Trump's proposal to rid the labor market of the undocumented. AAF culled Pew Research Center data and Labor Department figures to gauge the industry-level employment impact, and found private-sector payrolls would drop by 4 million to 6.8 million workers, resulting in an output decline of as much as $623.2 billion based on 2012 levels.  Holding the shares of each industry's workers who are undocumented constant for the 2015 annual data, the projections are stark. For nine of 12 industry categories, mass deportation would mean dropping even below employment levels in 2007, the year leading up to the last recession. While 2007 was a decent year for the labor market -- joblessness averaged 4.6 percent and payrolls were still steadily accelerating -- deportation would cut the workforce below those levels Whether those jobs would be filled by documented Americans who are still on the sidelines seven years after the start of the expansion is unclear.  Based on their share of workers who are undocumented, the agriculture (16.1 percent) and construction (12.2 percent) industries would take the biggest hits. Construction and educational and health services would be the furthest behind their 2007 levels, by 3.1 million and 2.9 million.  The industry data AAF considers are not identical to the categories you'll be able to track in Friday's jobs report, but largely match up. The monthly Labor Department release is for non-farm payrolls, which by definition excludes agriculture, while government jobs are excluded from the AAF data, which only consider private employment.  While policy changes implemented by a leading White House contender would slash overall employment, for now, Jobs Day enthusiasts are expecting relative calm. Private employers added about 195,000 workers in April, close to the 213,000 average in the year through March, according to the median in the Bloomberg survey ahead of Friday's report. If the April forecast pans out, business payrolls would total almost 122 million, compared with 116 million at the end of 2007.  Trump spokesperson Hope Hicks didn't immediately respond to an e-mailed request for comment on the study.
By deporting all undocumented workers, nine of 12 private payrolls categories would slump below their levels at the last recession's start