The problem of climate change seems to be a tragedy of the commons: despite the global benefits of reducing green-house gas emissions, no individual has any incentive to reduce his or her own emissions. Yet many people are making efforts to reduce emissions and putting pressure on businesses and...

Contingent liabilities create management problems for governments. They have a cost, but judging what the cost is and whether it is worth incurring is difficult. Except in the case of contingent liabilities created by simple guarantees of debt, governments usually can incur contingent...