(Yicai Global) July 13 -- Adorable but sometimes criticized as useless and expensive, giant pandas can now proudly say they are contributing members of society.

A study published Thursday in Current Biology, an American academic journal published by Cell Press, concludes that panda reserves create between 10 and 27 times as much value as they cost in maintenance.

China started protecting panda habitats in the 1960s and now has 67 reserves that together cover more than 33,000 square kilometers. All of this costs Chinese taxpayers roughly $255 million a year.

But the researchers found that giant pandas and their reserves created an estimated value of $2.61 billion per year in China, and $6.9 billion per year globally as of 2010.

"Many detractors have argued that spending valuable resources on panda conservation is wasteful," said Wei Fuwen, a researcher at the Chinese Academy of Sciences and author of the study. "Our analysis contradicts this view and demonstrates clearly the great value of the panda, both for its cultural and intrinsic value and for the ecosystem services provided by panda reserves."

Wei and his fellow researchers found that giant panda reserves benefit local residents and economies, as well as improve the larger ecosystem; they help purify the air, regulate the climate, and retain water. G