Economist Stephen Levy says nearly half of all the California jobs lost since 2005 were tied to construction.

"We went from building 200,000 homes five years ago to building 35,000 last year."

Levy heads a Palo Alto-based think tank called the Center for Continuing Study of the California Economy. His latest research finds that in the past five years, construction spending plunged 60% in California…compared with 25% nationwide.

Pro-business groups say companies are leaving California and taking manufacturing jobs with them because of high taxes. But Levy says California hasn't lost that many manufacturing jobs compared with the rest of the country.

"…which is understandable if you think of all the job losses in Detroit for automobiles and in North and South Carolina, the big manufacturing states."

Meanwhile, a second recent study by the Public Policy Institute of California found that relocations only amounted for less than two-percent of the state's job losses from 1992 to 2006.