Lindahl equilibrium is an economic framework for understanding the efficient and equitable allocation of public goods. Named after Swedish economist Erik Lindahl, the framework captures his insight that public goods should not be provided according to income or ability to pay, but rather by each individual's benefit from the good.

In Lindahl equilibrium, the decision of whether to provide a public good is based on the sum of individuals' willingness to pay for the public good. This perspective breaks away from the traditional "means test," which assumes that the required public goods can be provided if the government has sufficient resources. Instead, with Lindahl equilibrium, each person contributes a fee that is proportional to their personal benefit from the public good, rather than to their income or ability to pay. This type of fee structure results in both efficient allocation of resources and a fairer and more equitable distribution of the cost burden.

The concept of Lindahl equilibrium serves to highlight the coordination problems that exist in the provision of public goods. If such goods are provided, there is the issue of how to determine the 'right' amount– too much and it becomes overprovision, where resources are wasted, too little and there may be underprovision and individuals may be unable to attain the desired benefit from the good.Lindahl equilibrium helps to address this problem of reaching a fairer and equitable distribution of costs while still providing the desired level of public goods or services.

However, practical implementation of a Lindahl tax is a significant challenge. It relies on comprehensive data on individual welfare and the value of the public good to each person. This data is often unobtainable or difficult to collect, which renders a Lindahl tax impossible to implement. Political issues can also impede its implementation. An effective Lindahl equilibrium necessitates a perfectly inelastic demand for public goods—however this is seldom an accurate representation of public sentiment. These issues cast doubt on how useful the concept actually is in practice.

Overall, Lindahl Equilibrium is a theoretically appealing way to understand the efficient and equitable allocation of public goods. Lindahl's framework ensures that the burden of paying for public goods is distributed fairly among its consumers and that the level of provision is derived from a carefully considered determination of individual benefit. Nonetheless, various political, economic and practical issues persist which render the concept of Lindahl equilibrium largely inapplicable in practice.