Horse trading

Horse trading, in its literal sense, is the buying and selling of horses, also called "horse dealing". Due to the difficulties in evaluating the merits of a horse offered for sale, the sale of horses offered great opportunities for dishonesty, leading to use of the term horse trading (or horsetrading) as a widespread metaphor for complex bargaining or other transactions, such as political vote trading. It was expected that horse sellers would capitalize on these opportunities and so those who dealt in horses gained a reputation for underhanded business practices.