When in forms other than money, financial capital may be traded on bond markets or reinsurance markets with varying degrees of trust in the social capital (not just credits) of bond-issuers, insurers, and others who issue and trade in financial instruments. When payment is deferred on any such instrument, typically an interest rate is higher than the standard interest rates paid by banks, or charged by the central bank on its money. Often such instruments are called fixed-income instruments if they have reliable payment schedules associated with the uniform rate of interest. A variable-rate instrument, such as many consumer mortgages, will reflect the standard rate for deferred payment set by the central bank prime rate, increasing it by some fixed percentage. Other instruments, such as citizen entitlements, e.g. "U.S. Social Security", or other pensions, may be indexed to the rate of inflation, to provide a reliable value stream.