As it considered whether to allow high-volume hydraulic fracturing in New York, the administration of Gov. Andrew Cuomo sought guidance from health officials on possible impacts to air and water quality.
Pennsylvania officials also have studied possible health impacts of the technique known as fracking, but did so after the practice was well underway here.
Was New York exercising more caution with the health of its citizens?
Perhaps, but when Cuomo's administration announced Wednesday that it would ban the technique for extracting natural gas from shale deposits, analysts said the decision was as much about politics and economics as it was about health.
Studies suggest that far less natural gas is easily recoverable in the New York portion of the Marcellus Shale geologic formation than in Pennsylvania.
And New York already is getting some of the jobs and spending associated with the high-volume fracking occurring in nearby Pennsylvania - but with none of the costs, said Susan Christopherson, chair of the Cornell University department of city and regional planning.
Throw in the fact that New York is a blue state with strong public opposition to the practice, where state finances are healthy, unlike in Pennsylvania, and it is easy to see why Cuomo wants a ban, she said.
"I think he made not just a health calculation, even though I think that played a role in it," said Christopherson, an economic geographer. "He made a political and an economic calculation too."
Cuomo said last week that the decision was based on science, and that he left it up to his commissioners of health and environmental conservation. They in turn said the science was unclear, but the potential risks were great enough to err on the side of caution.
The governor's office did not return a request for comment Friday.
Still unclear is what New York's move means for Pennsylvania, where high-volume fracking - the use of pressurized fluids to crack open gas deposits in shale - yields trillions of feet of natural gas a year.
Gov.-elect Tom Wolf said last week that he disagreed with New York's ban, vowing instead to ensure that the practice is performed safely. He also has proposed a 5 percent tax on gas extraction.
Yet a spokesman said Wolf continues to oppose drilling in the Delaware River Basin.
That region is overseen by a commission with members from Pennsylvania, New Jersey, New York, and Delaware, along with a representative from the federal government.
Drilling in the basin has been on hold amid disagreement among the participating states. Delaware and New York are expected to vote no on any proposal to allow drilling, whereas Pennsylvania under Gov. Corbett has been squarely in favor. Representatives from New Jersey and the U.S. are said to be reluctant to cast a deciding vote.
Now with Wolf in the "no" camp and New York reaffirming its position against high-volume fracking, environmental advocate Maya K. van Rossum said she was optimistic.
"We're hopeful that this solidifies protection for the basin," said van Rossum, head of the Delaware Riverkeeper Network.
New York continues to allow conventional, low-volume fracking in carbonate and sandstone formations.
The high-volume variety is far different, requiring up to 100 times as much pressurized fluid to get the job done, because shale is impermeable, said Anthony Ingraffea, an emeritus professor of environmental engineering at Cornell University.
In its 184-page report, the New York Department of Health reviewed evidence that the technique harms air and water quality, and found that more study was needed.
Acting health commissioner Howard Zucker said it was "reckless to proceed in New York until more authoritative research is done."
Among other studies, a review of impacts on drinking water by the U.S. Environmental Protection Agency is still underway.
David J. Spigelmyer, president of the Marcellus Shale Coalition industry group, said New York's ban was a case of "political ambition" trumping the rights of landowners in the Southern Tier - the area along the border with north-central Pennsylvania where drilling was likely to take place.
"Pennsylvania is proof-positive that with strong and common sense regulations, along with continuous technological advancements, shale development is a win-win for the state and our nation's environment and the economy," Spigelmyer said in a statement.
Ingraffea, the Cornell engineer, said there was little potential for a gas bonanza in New York. He cited two independent studies which found that at current low prices, drilling for gas in New York shale is not commercially viable.
The shale formation yields less gas in New York than in Pennsylvania for several reasons, he said. In its northern reaches, the formation becomes thinner, meaning it contains less gas, and shallower, meaning the pressure is lower.
At lower pressure, the decaying organic materials that turn into gas have not been "cooked" enough to yield rich deposits, he said. Gas at lower pressure also is harder to extract.