Lenders may be willing to remove family members from the residual calculations if a non-purchasing spouse or a working-age child has sufficient income to cover their monthly debts. This can include children who receive Social Security or disability income, child support and other forms of income, provided it’s likely to continue for at least three years.
Residual income is calculated as net income less a charge for the cost of capital. The charge is known as the equity charge and is calculated as the value of equity capital multiplied by the cost of equity or the required rate of return on equity. Given the opportunity cost of equity, a company can have positive net income but negative residual income.