Massachusetts gained nearly 39,000 new jobs during the first nine months of 2011, according to a new report that paints a far brighter picture of the state's recent economic growth than did federal statistics released last month.
The analysis issued Wednesday by MassBenchmarks, a journal of the Massachusetts economy, was the latest in a series of often contradictory estimates of employment growth that had left in doubt the true pace of recovery.
State officials had initially estimated that more than 40,000 new jobs were added over the full year, putting Massachusetts closer to the leading edge of the recovery. But in March, the federal Bureau of Labor Statistics released a new estimate pegging job growth at only 9,100 last year, which would have placed the state among the lower 20 percent for job growth.
The latest, unofficial analysis by economists for MassBenchmarks swings the pendulum back in the opposite direction. Using new available data, MassBenchmarks estimates that the state added 38,900 jobs between January and September, a figure that's 36,000 higher than the current official BLS estimate for the same nine months.
MassBenchmarks is published by the Donahue Institute at the University of Massachusetts in cooperation with the Federal Reserve Bank of Boston.
The discrepancy is tied to varying methodology used for calculating job growth and the substantial lag time involved in getting data from what many economists consider to be the most reliable measuring stick: a census of Massachusetts employers who participate in the state's unemployment insurance system.
Earlier estimates were based on payroll surveys that economists consider to be less reliable.
"Given the problems faced by the monthly payroll survey in accurately measuring employment trends, and the large revisions in job counts, it is important to incorporate accurate information into our understanding of employment trends when it becomes available," said Alan Clayton-Matthews, a Northeastern University economist and senior contributing editor for MassBenchmarks, in a statement.
"At least for the first three quarters of last year, the pace of job creation appears to have accelerated moderately from 2010," he said.
Democratic Gov. Deval Patrick's administration had challenged the gloomier federal estimates, while Republican lawmakers had seized upon them to support their contention that Patrick was overstating the strength of the state's economy.