The percentage of the value of a transaction which a buyer or seller is required to deposit as a margin. This is needed to protect one party to a contract against loss if the other side's commitments are not met.

• auditor
• autarky
• authorized capital
• autocorrelation
• automatic stabilizers
• automation
• autonomous consumption
• autonomous investment
• average
• average cost
• average cost curve, U-shaped
• average cost pricing
• average propensity to consume
• average propensity to import
• average propensity to save
• average revenue
• avoidable cost
• avoidance, tax
• axiom
• axis
• back door
• backward-bending supply curve
• backward integration
• BACS
• bad debt