Polluters get a free ride. That needs to change.

Global GDP now exceeds $100 trillion a year. The externalities we create in earning it — the pollution, the displacement, the deferred harm — are nowhere on the balance sheet. By bringing ethics and economics together, we can start to account for them, and build a more sustainable and equitable market economy.

An externality is what happens when a transaction's costs land on people who had no part in it. People elsewhere, and people not yet born, pay what we defer to them.

The result: damage on a civilisational scale, unacknowledged and unfunded. Our system of economics encourages us to look away from what others must pay — we privatise profits and socialise costs to the commons. We have cheated our way into a comfortable life — for some of us, anyway — by not paying our dues.

For example, the legacy of tetraethyllead and lead-based paint chips is still damaging the brains of inner-city children today, decades after we stopped using them. The behaviour has reformed (thank goodness), yet the pollution remains, and will stay there for generations to come.

Good governance tries to manage externalities, but usually after the damage is done. Someone creates a mess; an authority orders a fine. Only the grossest harms get noticed and policed — assuming the authorities cannot be bought off.

We have mastered the art of producing things of terrific complexity at immense scale, cheaply. The art of consuming cleanly and fairly has barely begun.