Income from Domestic Product Accruing to Private Sector:
This refers to that part of the domestic product at factor cost which accrues to the private sector of the economy. It is estimated as follows:
NDP_FC-Income from domestic product accruing to Government –savings of non departmental enterprises.
Private Income:
It refers to the income earned by the individuals from whatever source within the domestic territory of the country and abroad. It is obtained as follows;
Private Income = Income from domestic sources accruing to private sector -NFIA + Net Current transfers from the rest of the word + Current Transfers from the Government + Interest on National Debt.
Personal Income:
This is the aggregate money payments actually received by the individuals or households within the domestic territory of the country during an accounting year.
Some part of the national income is actually not received by individual. For example corporate income taxes are a part of national income but they are not received by the individuals. So to arrive at personal income corporate taxes must be subtracted from National Income. Similarly social security contributions, undistributed corporate profits etc. are reduced from the national Income.
Then, there are some incomes received which are not currently earned (e.g., transfer payments, which include old-age pensions, unemployment relief, other relief payments, interest payment on the public debt, etc.)
So we arrive at Personal Income with following formula:
Personal Income = National Income – Social Security Contributions –Corporate Income Taxes – Undistributed Corporate Profits + Transfer Payments
Disposable Income DI
The Personal income is the income of an individual. He / she pays personal taxes , property taxes etc. and after that whatever left to him or her is Disposable Income.
Personal Income –Personal taxes =Disposable Income
There is another formula:
Disposable Income = Consumption + saving.