Nearly 48,000 people have been hired in the last year by industries related to drilling in the Marcellus Shale, and 71 percent of those people were Pennsylvania residents. Nine thousand of them were hired in the first three months of 2011.

The average salary was higher than the statewide average.

And the rate of hiring is accelerating.

While there has been much talk of the economic impact of the Marcellus, most of it has been anecdotal, until the Department of Labor and Industry quietly published its most up-to-date hard numbers about two weeks ago.

The report was released with such little fanfare that even Katie Klaber didn’t know about it. Klaber is the head of the Marcellus Shale Coalition, the main industry group representing the top 20 companies active in Pennsylvania.

Labor and Industry spokesman Christopher Manlove said the department publishes a monthly “Fast Facts” jobs report, and since “we obviously get a lot of questions about Marcellus Shale ... it just stood to reason to make a Marcellus Shale version of fast facts.”

It wasn’t “marketed” in any way, he said, but it was available to anyone visiting the department’s website.

The report’s statistics surprised even Klaber, the most vocal proponent of Marcellus Shale drilling as an economic boon to the commonwealth.

There’s been nearly a 1,300 percent increase in core Marcellus industry jobs in the Northern Tier counties of Bradford, Sullivan, Susquehanna, Tioga and Wyoming since 2008.

The central counties including Lycoming, Clinton, Centre, Columbia and Northumberland saw an increase of more than 660 percent.

Employment in the mining and logging sector, which includes Marcellus drilling, has increased more than 57 percent in the last decade, with more than half that increase occuring in the last 12 months.

The number of new hires in the first three months of 2011 is nearly double what it was the same time last year.

With just the 9,000 new hires in the first three months of this year, Klaber said, “If even a fraction of those were announced by some new company coming in, people would be falling over themselves. This is happening in multiples of what would have been done in the past with taxpayer dollars. Here the market economy is doing it independently.”

Critics of the industry have noted it is by nature cyclical, and they say the jobs won’t last. After the drilling boom is done, the jobs go bust.

That’s a long way away, Klaber said.

“Will it eventually track more closely to the regional economy? Probably, but we’re not through this yet. It’s going to be bigger before we’re done,” she said.

“The growth rate may taper off,” she said, “but the relative proportion of Marcellus jobs to the rest of the state economy is what we’ll live with for years to come.”