← Basic economics

Markets & failure

Markets work well when the costs and benefits land on the people choosing. They fail when someone else pays, information is bad, or one seller dominates.

  • Demand
  • Private cost
  • Social cost

Market sells 8 units at £6.00. Counting the spill, 6 units at £7.00 would be better. The extra units look cheap because someone else pays.

Toy numbers. The spill is a cost left out of the price.

Takeaway

  • A market can be efficient and still miss a cost.
  • Externalities, public goods and thin competition are the usual failure modes.
  • “Failure” means the price signal is incomplete, not that trade is bad.