Donald Trump’s new immigration policies—including deporting, the White House claims, about 750 immigrants a day on average—are helping drive up prices, Moody’s chief economist Mark Zandi told Fortune.

He says if Trump continues deporting immigrants at the current rate, inflation will go from 2.5% to somewhere close to 4% “by the time it hits its peak early next year.”

Zandi says his stark prediction is based on recent inflation data. “Foreign-born labor force is declining, and the overall labor force has gone flat since the beginning of the year,” he added. “That’s causing tightening in a lot of markets, adding to costs and inflation.”