Dallas home prices are climbing rapidly, and homebuilders are complaining about labor shortages and soaring wages for construction workers. But something else makes this housing boom different from others: Immigrants aren't riding to the rescue.

For decades, Mexicans and other foreign-born workers have been coming to Texas to build homes, apartments and office towers. By one estimate, they fill almost half the construction jobs in the state, which is about twice as many as in the rest of the nation.

That total includes legal and unauthorized immigrants. In the construction industry, both groups are roughly the same size in the U.S., according to the Pew Research Center.

Texas has been a job magnet for immigrants because of close ties with Mexico and the amount of work available. But the flow of people has slowed significantly -- first, as a result of the housing bust and deep recession, and more recently with the focus on immigration laws and border security.

“We’ve been very reliant on these workers since the late ‘70s,” said Pia Orrenius, senior economist at the Federal Reserve Bank of Dallas. “But the age of cheap labor in the U.S. is over.”

It’s not just the anti-immigrant stance pushed by lawmakers and President Donald Trump. After the recession, Mexico’s economy recovered faster so many Mexicans who had left never came back. The demographics in Mexico also have changed, with more dual-earning households and fewer young people.

Since the recession, more Mexicans have departed the U.S. than have moved to this country, Pew reported.

During the previous housing boom, from 2002 to 2007, Texas added almost 660,000 international immigrants, according to the Census Bureau. In the past five years, as homebuilding bounced back, international immigration was 40 percent lower.

A related metric is starker. From 2000 to 2005, Texas added almost half a million unauthorized immigrants, Pew said. But that total has been relatively flat since the recession and declined slightly after 2011.

“All the focus on the border and criminals is frustrating, because the construction industry has a big help-wanted sign out,” said Phil Crone, executive officer of the Dallas Builders Association, which has almost 1,000 members.

The group has been working with high schools and community colleges to stoke interest. Builders often invite students to job sites, where many are impressed by the work being done on million-dollar homes. Unfortunately, he said, many of the interested students are not U.S. citizens.

“That seems like a tailor-made opportunity to fix the labor shortage,” Crone said.

In the Dallas-Plano-Irving area, just over 81,000 worked in the construction trades in February, according to government data. To fill current demand in the business, the industry needs up to 99,000 workers -- not years in the future, right now.

That estimate from Meyers Research is based on a model that considers the growth in building permits and other trends. The research firm also reported that millennials are underrepresented in construction, even while they flock to physical work for solar panel companies.

In a recent survey in Builder magazine, just 3 percent of young adults said they were interested in a career in construction. In Texas, nearly 7 percent of private jobs are in the field. In addition to today's demand for workers, many skilled tradesmen are in their 40s and 50s, so retirement is not far off.

The number of Texas residential construction workers recently surpassed the peak set before the housing bust. And their average weekly wages rose almost 22 percent from the first quarter of 2012 to the first quarter of 2016, according to government data and the Texas A&M Real Estate Center.

That figure is adjusted for inflation and compares with a 12 percent gain for the same workers nationwide. For all private jobs in Texas, the average gain was just over 2 percent.

In Collin County, these construction workers earned almost $98,000 in the past year. That’s $44,000 more than the average for all private employees in the country.

Higher labor costs are a major contributor to the rise in housing prices. Since 2012, the median price of a new home in the Dallas area has increased 46 percent, Meyers Research said. In the previous boom, U.S. housing prices grew faster than in Texas. This time, Texas gains are well ahead.

The immigration slowdown isn't the only reason, but it's one of them. In a recent working paper, Orrenius explored a temporary visa program for labor shortages in the U.S. She worked on the subject for the White House a decade ago, and the paper notes that the ideas are the authors' -- not the Dallas Fed's.

Only 5,000 permanent resident visas are awarded annually to low-skilled workers, she wrote, so employers largely turn to unauthorized workers. She said a flexible system could be designed to benefit employers and immigrants, and not undercut U.S. workers.

She estimated that 100,000 temporary visas could be granted annually, depending on market conditions. If the U.S. doesn’t welcome outsiders, she worries that we’ll start to resemble Europe.

“Fewer projects will get done, prices will go up, and would-be homebuyers will be renters,” Orrenius said.