There is an important and quite general feature to the commons problem—what economist Thomas Schelling called “the tyranny of small decisions.” When deciding whether to add another cow to your herd, you are not choosing to destroy a common resource in order to get a little more milk. Faced with that choice, you might refrain. The choice you see is a little more milk in exchange for a little less grass. Good deal. So, commons problems are marked by conflicts between individual and collective interests and between short-term and long-term interests. It is from this tragic dilemma that we must escape.