When the Hoover Institution took a close look at California’s migration patterns, they discovered that California’s middle class is leaving the state in record numbers.

It is widely known that California is home to more than 10 million immigrants—one in four of the foreign-born population in the U.S. now lives in California.

Foreign-born residents also represent more than 30 percent of the population of seven California counties: Santa Clara, San Francisco, Los Angeles, San Mateo, Imperial, Alameda, and Orange. And about half of the children in California have at least one immigrant parent.

Breitbart New has reported extensively about the exit of California residents. In 2013 (the most recent data available)102,972 Californians left for other states, and only 66,294 individuals from other states moved to California. The only reason that the Golden State achieved a net population gain was that 169,266 was mostly due to illegal/undocumented immigrants streaming into California.

According to Hoover Institution research fellow Carson Bruno, who studies California’s political and policy landscape, “Not only are Californians leaving the state in large numbers, but the people heading for the exits are disproportionately middle class working families — the demographic backbone of American society.”

Bruno argues, “while there is a narrative that the rich are fleeing California, the real flight is among the middle-class.” His research documents that for middle-class working young professional families, California is an extraordinarily high cost-of-living state:

The median California home value per square foot averages 2.1 times higher than Arizona, Texas, Nevada, Oregon and Washington’s:

California’s energy costs are about 1.5 times higher than neighboring states; and

The Golden State’s now ranks 6th nationally for state-local tax burdens.

Bruno noted that the national average for the percent of middle-class households that used more than 30 percent of their income to cover rent was 31 percent. But for California in the last decade, the percentage of rent “cost burdened” had jumped from 38 percent to over 53 percent.

The average percent of “cost burdened” with a payment of more than 30 percent of income to buy a home in the United States is about 40 percent. But in California, the percent with a mortgage that are “cost burdened is over 66 percent.

Demographer Joel Kotkin of Chapman University recently agreed, “California’s middle class is being hammered.” He notes that state home ownership declined from 59 percent in 2009 to 54 percent today. Despite being one of the states with the highest rates of home ownership in the 1950s, California now ranks second from the bottom, ahead of only New York.

Bruno acknowledges that “California has added 2.1 million jobs since 2010,” but the vast majority have been in low paying service jobs. In the traditionally high paying middle class job bastions of construction, finance and manufacturing, employment is still below the 2007 levels before the Great Recession.