The number of people in the Orange County labor pool dropped sharply in September, causing the county's jobless rate to dip to 3.1% from 3.3% in August.
September's unemployment was the lowest in the county since April and was the third-lowest in the state, trailing slightly behind the 2.7% rate for San Mateo County and 2.9% for Marin County.
The U.S. jobless rate for September was 5.3%, down from 5.5% in August, and the California rate was 5.2%, down from 5.6%.
The slight decline in unemployment in Orange County last month was caused largely by an apparent exodus of potential workers, according to state Employment Development Department labor market analysts.
The total civilian labor force in the county dropped by 11,000 to 1.33 million in September, according to EDD estimates.
EDD labor analyst Daniel Johnson has said that a continuing decline in the total labor force would indicate that high housing prices and other living costs in the county could be forcing some workers to seek homes and jobs in other areas.
He said it would take 3 or more months of a declining labor force to determine whether the labor pool shrinkage is a statistical aberration or an actual trend.