Contrary to popular perceptions, immigrants in California are not responsible for taking away jobs, according to a recent UC Davis study that debunks some myths about immigrants' relationship to work and welfare. In reality, structural changes in the global economy, cuts in defense spending and welfare retrenchment have transformed the California labor market and reduced job opportunities, say Michael Peter Smith, a community studies and development professor, and Bernadette Tarallo, a research sociologist with UC Davis' applied behaviorial sciences department. Their study was published by the California Policy Seminar, a joint UC-state government program. The study also debunks the notion that the ethnic enclave economy provides genuine employment and economic opportunities for new immigrants. Instead, such enclaves serve to reinforce immigrants' difficulties in learning and speaking English and inhibit upward mobility.