The endowment effect is a cognitive bias in which individuals tend to value an object or possession more highly simply because they own it. This can lead to individuals placing a higher value on an object they already possess compared to the value they would place on the same object if they did not own it. The endowment effect has been studied in various fields, including psychology, economics, and marketing, and has important implications for consumer behavior, decision-making, and negotiations. Researchers often investigate the causes and consequences of the endowment effect, as well as ways to mitigate its effects in different contexts.