A Lindahl equilibrium is a state of economic equilibrium under a Lindahl tax as well as a method for finding the optimum level for the supply of public goods or services that happens when the total per-unit price paid by each individual equals the total per-unit cost of the public good. It can be shown that an equilibrium exists for different environments.[2] Therefore the Lindahl equilibrium describes how efficiency can be sustained in an economy with personalised prices. Leif Johansen gave the complete interpretation of the concept of "Lindahl equilibrium", which assumes that household consumption decisions are based on the share of the cost they must provide for the supply of the particular public good.[3]

The importance of Lindahl equilibrium is that it fulfills the Samuelson condition and is therefore Pareto efficient,[2] despite the good in question being a public one. It also demonstrates how efficiency can be reached in an economy with public goods by the use of personalised prices. The personalised prices equate the individual valuation for a public good to the cost of the public good