If the consumption function c=c0+bY, we can deduce the saving function s=-c0+( 1-b)Y, and savings = investment, so -c0+( 1-b)Y=i, c0, b, i are all known, and we can get the equilibrium income y. If only tax (T) and transfer payment (Tr) are considered, then disposable income YD = Y-T+TR. Accurately speaking, disposable income is equal to national income MINUS all taxes, corporate savings and depreciation, plus expenditures and other transfer payments, as well as government interest payments.

1. Disposable income is the total after-tax income that a person, a household or a family can spend or save. Consumer's income and expenditure pattern is a valuable demographic factor. Although it is difficult to accurately calculate with the concepts of per capita GDP, per capita income, consumer price index and economic cycle, its influence on consumption power or purchasing power is obvious. The statistical data of per capita disposable income based on the income sampling survey of urban and rural residents is one of the important basic data in China's national economic accounting system. It is not only a basic index to measure the living standard of residents in a country or region, but also plays a very important role in macroeconomic theory and empirical research, and also plays an important role in the formulation of national macroeconomic policies.

2.yd is disposable income and y is national gdp. This formula means that the government should consider increasing the per capita disposable income through transfer payment or directly reducing the tax rate of some taxes, so as to stimulate consumption and expand domestic demand. In addition, tax should be levied on asset retention to improve investment relations and balance social income. Disposable income is the income you get. That is, the remaining part of wage income is deducted from basic old-age insurance, basic medical insurance, unemployment insurance, provident fund and personal income tax. The money left after deducting them is disposable. "Gross Domestic Product" GDP is a total index reflecting the final production results of a country, while "national disposable income" NDI is a total index measuring the final income of a country, and GDP represents the total production; NDI stands for total income.

3, national income related:

Income composition of two departments, three departments and four departments (Y-AE model) and savings-investment identity.

Description: _ bet: c = α+β yd; β: _ QIA QIA QIA QIA QIA QIA QIA QIA QIA QIA QIA199 National income: Y

Tax t = t0+ty; TR:_ Bodhisattva ц; _ c:M = M0+γY，γ:_ c。