Here's part of the story - for more, the link is here:
“It only takes a small assumption to create a result that is much higher or lower,” said Matthew Rousu, associate professor of economics at Susquehanna University in Selinsgrove, Pa., and creator of a website designed to evaluate such studies.
Confusion and bias among those economic reports led to the site’s creation. The Economic Impact Review will post and review economic impact studies.
Though the initial emphasis is on Marcellus Shale studies, the plan is to expand the reviews to other economic-impact reports.
The site is not funded by the oil and gas industry or by any environmental group, Rousu said.