The Massachusetts economy made strong job gains in the past two months, the Executive Office of Labor and Workforce Development reported Thursday, but economists said it is difficult to gauge improvement in state labor markets given uncertainty that the employment increases will stand up to later revisions.
Just two weeks ago, they noted, revisions of 2011 statistics cut employment growth for the year by more than 75 percent, to about 9,000 jobs from initial estimates of nearly 41,000.
In February, the state reported, Massachusetts employers added 9,100 jobs as the unemployment rate held steady at 6.9 percent, below the national rate of 8.3 percent. The state also revised job growth figures for January, more than doubling the number of jobs added, to 13,900 from a previous estimate of 6,600.
“If these hold up, they are pretty good numbers,’’ said Andre Mayer, senior vice president of research at Associated Industries of Massachusetts, a trade group.
But Mayer and others said they are wary of drawing hard conclusions about the strength of the state’s recovery as a result of the 2011 revisions. Before those revisions, it seemed the state’s economy was growing significantly faster than the nation’s.
Instead, the overall Massachusetts economy appears to have been growing at roughly the same rate as the nation, while creating jobs at a much slower pace.
“Given the experience,’’ said Northeastern University economics professor Alan Clayton-Matthews, “it’s hard to tell how strong employment growth has been recently.’’
Employment data is subject to frequent revision. At the beginning of each year, the US Labor Department adjusts its preliminary state estimates for the previous year as employers report hard data on the number of workers on their payrolls. But since that data take longer to collect, the information does not show up in monthly snapshots of employment released by state labor agencies.
Massachusetts was not the only state to see big revisions. Several states - including Alabama, Maine, and Montana - swung from net job gains in 2011 to net losses, according to IHS Global Insight, a Lexington forecasting firm. In California, job gains were slashed by 95,000, to about 168,000 from 263,000. In New York, following the annual revisions, 2011 job gains increased to about 125,000, from less than 90,000.
Estimates for the first two months of 2012 show solid job growth in Massachusetts. In February, most of the 10 private sectors tracked by the state added jobs, led by leisure and hospitality, which gained 4,800.
Clayton-Matthews, however, said those gains could be overstated. Employment in leisure and hospitality businesses, such as hotels and restaurants, is highly seasonal, and formulas that adjust statistics to account for seasonal variations can skew the numbers.
“We know that sector is suspect for very large increases in some months and later, very large job decreases,’’ Clayton-Mathews said.
Other sectors adding jobs last month included trade, transportation, and utilities, which gained 2,600; education and health services, which gained 1,700; and professional, scientific, and business services, which grew by 900.
Those additions were offset by losses in other sectors, including financial services, which shed 800 jobs, and the information sector, which lost 500.
Mayer said he remained optimistic about the state’s economy because the February job gains appear plausible, in part because they are in line with national trends. The nation added 227,000 jobs in February.
“We had a serious loss of [labor force] participation in this last downturn,’’ Mayer said, “so it’s very important to get people back to work.’’