Last July, construction site superintendent Robby Robertson warned his $20 million recreation center project in Mobile, Alabama, would likely be delayed for three weeks. He told Reuters that half of his workers stopped showing up to the site after an Immigration and Customs Enforcement raid on another site in Florida, nearly 230 miles away, afraid of facing the risk of deportation.

The delay would cost Robertson an estimated $84,000, with $4,000 of daily “liquidation damages” mounting for each day the project dragged past its Nov. 1 deadline.

Robertson’s problem may be a nationwide challenge. New data has confirmed economists’ concern that the Trump administration’s immigration crackdown has led to fewer jobs in critical industries, particularly construction, reifying fears of labor shortages, delays, and ultimately passed-down costs to homebuyers.

A working paper recently published by the National Bureau of Economic Research found employment among likely undocumented immigrants dropped 4% on average in areas where ICE conducted recent raids. Construction was the most affected industry the researchers tracked, with employment dropping 7.5% for undocumented workers. The Associated General Contractors of America (AGC) estimates 35% of construction workers are immigrants.