That income is considered residual income because as long as the apartment is rented and the rent is collected, the income is earned without additional effort. The effort came when the property was purchased and a tenant was found. Each month after that, the money automatically is paid without buying the apartment again or finding the same tenant each month.

In the residual income model, the intrinsic value of a share of common stock is the sum of book value per share and the present value of expected future pershare residual income. In the residual income model, the equivalent mathematical expressions for intrinsic value of a common stock are V0=B0+∑t=1∞RIt(1+r)t=B0+∑t=1∞Et−rBt−1(1+r)t=B0+∑t=1∞(ROEt−r)Bt−1(1+r)t

You must sacrifice the pleasures of today for the freedom you will earn tomorrow. In my 20s, I shared a studio with my best friend from high school and drove beater cars worth less than 10% of my annual gross income. I'd stay until after 7:30 p.m. at work in order to eat the free cafeteria food. International vacations were replaced with staycations since work already sent me overseas two to four times a year. Clothes were bought at thrift shops, of course.

*In equity valuation, residual income represents an economic earnings stream and valuation method for estimating the intrinsic value of a company's common stock. The residual income valuation model values a company as the sum of book value and the present value of expected future residual income. Residual income attempts to measure economic profit, which is the profit remaining after the deduction of opportunity costs for all sources of capital.*