In his classic book, "The Logic of Collective Action," the late great Mancur Olson explained that the hardest policies to implement are those with diffuse benefits and concentrated costs.
Olson’s argument was straightforward: Individuals bearing the costs will vigorously oppose the policy, while the beneficiaries will free ride, preferring that someone else take up the cudgels.
Olson’s insight applies to the single most pressing policy challenge facing humanity today, namely climate change. The starting point for addressing it, economists agree, is a tax on carbon.