Home equity is the market value of a homeowner's unencumbered interest in their real property—that is, the difference between the home's fair market value and the outstanding balance of all liens on the property. The property's equity increases as the debtor makes payments against the mortgage balance, and/or as the property value appreciates. In economics, home equity is sometimes called real property value. Technically, home equity has a zero rate of return and is not liquid. Home equity management refers to the process of using equity extraction via loans at favorable, and often tax-favored, interest rates to invest otherwise illiquid equity in a target that offers higher returns. Homeowners acquire equity in their home from two sources. They purchase equity with their down payment, and the principal portion of any payments they make against their mortgage.