There is some controversy surrounding the use of retraining to offset economic changes caused by free trade and automation. For example, most studies show that displaced factory workers in the United States on the average have lower wages after retraining to other positions when a factory is closed due to offshoring. A similar issue surrounds movement from technical jobs to liaison jobs due to offshore outsourcing. Such changes may also favor certain personality types over others, due to the changing tasks and skills required. Other research estimates that one academic year of such retraining at a community college increases the long-term earnings by about 8 percent for older males and by about 10 percent for older females.