Residual income models of equity value have become widely recognized tools in both investment practice and research. Conceptually, residual income is net income less a charge (deduction) for common shareholders’ opportunity cost in generating net income. It is the residual or remaining income after considering the costs of all of a company’s capital. The appeal of residual income models stems from a shortcoming of traditional accounting. Specifically, although a company’s income statement includes a charge for the cost of debt capital in the form of interest expense, it does not include a charge for the cost of equity capital. A company can have positive net income but may still not be adding value for shareholders if it does not earn more than its cost of equity capital. Residual income models explicitly recognize the costs of all the capital used in generating income.
Loss of your job as a physician often means an expensive relocation to another city due to non-compete agreements.  It may also mean 6 months without income as you get a medical license, a DEA license, and/or go through the credentialing/privileging process.  You may have to sell your house at a loss or even liquidate investments in a down market to tide you over through a period of lost income.  Because of this, employers have an advantage over you in negotiations.  But if you have multiple streams of income, you don’t have to play by their rules and you retain negotiating advantage.  This is your F-You money because it allows you to say “F-You” to the employer and walk away from the job.  You know there will still be money coming in every month even without your main job.
The other equation of disequilibrium, if S + T + M < I + G + X in the five sector model the levels of income, expenditure and output will greatly rise causing a boom in economic activity. As the households income increases there will be a higher opportunity to save therefore saving in the financial sector will increase, taxation for the higher threshold will increase and they will be able to spend more on imports. In this case when the leakages increase the situation will be a higher level of equilibrium.

Residual income is the amount of net income generated in excess of the minimum rate of return. Residual income concepts have been used in a number of contexts, including as a measurement of internal corporate performance whereby a company's management team evaluates the return generated relative to the company's minimum required return. Alternatively, in personal finance, residual income is the level of income that an individual has after the deduction of all personal debts and expenses have been paid.