The use of misrepresentation for economic gain. The misrepresentation may be through positive statements, or conduct liable to mislead. Fraud includes obtaining goods on credit or loans which one knows cannot be repaid, continuing to trade when unable to pay one's debts, or making payments to creditors knowing that others with equal or prior claims cannot be paid. Fraud is difficult to prove, as its effects are hard to distinguish from those of bad luck or incompetence. Where fraud is proved, the courts have powers to undo transactions, and to take over the personal assets of officers responsible for fraud by companies.

• operational research
• opportunism
• opportunity cost
• optimal growth theory
• optimality, Pareto-
• optimization
• optimum currency area
• optimum savings
• optimum tariff
• option
• option value
• order book
• order-driven market
• order of integration
• orders, new
• ordinal utility
• ordinary least squares
• ordinary share
• organizational slack
• Organization for Economic Cooperation and Development
• Organization of Petroleum Exporting Countries
• organized labour
• organized sector
• origin
• oscillation