The Coase conjecture is an economic theory that suggests that when two parties are involved in a dispute, they will reach an agreement if they can negotiate without incurring any costs. This theory was put forward by economist Ronald Coase in 1960.

The Coase conjecture has been used to explain a number of real-world phenomena, such as why companies engage in mergers and acquisitions, and why some countries have more effective environmental regulations than others. In general, the theory suggests that when two parties are able to negotiate without incurring any costs, they are more likely to reach an agreement that is beneficial for both parties.

There are a number of criticisms of the Coase conjecture, including the fact that it does not always hold true in real-world situations. However, the theory remains a useful tool for understanding how parties can reach agreements in certain situations.