In the most recent example, the banking giant Wells Fargo noted last month what it called “considerable attention and controversy” surrounding mountaintop removal mining, and said that its involvement with companies engaged in it was “limited and declining.”
The bank was a small player in the sector, representing about $78 million in bonds and loan financing for such companies from 2008 to April of this year, according to data compiled by the Rainforest Action Network, an environmental group tracking the issue.
But the policy shift by Wells Fargo follows others over the last two years, including moves by Credit Suisse, Morgan Stanley, JPMorgan Chase, Bank of America and Citibank, to increase scrutiny of lending to companies involved in mountaintop removal — or to end the lending altogether.
via www.nytimes.com
It's not really the Coase Theorem, of course, but it is private action to correct a negative externality. If big mining companies can't get decent financing for their massive equipment then there will be fewer big mines.