1. Imputed value of rent for self occupied houses or offices is to be included.
2. Imputed value of services provided by owners of production units (family labour) is to be included.

1. The enterprises are classified into various industrial groups.
2. Factor incomes are grouped under labour income, capital income and mixed income.
i) Labour income - Wages and salaries, fringe benefits, employer’s contribution to social security.
ii) Capital income – Profit, interest, dividend and royalty
iii) Mixed income – Farming, sole proprietorship and other professions.
3. National income is calculated as domestic factor income plus net factor incomes from abroad.

The followings are some of the National Income Identities:
NNP = GNP - Depreciation
NNI = NNP - Indirect taxes
PI = NNI - Retained earnings, corporate taxes and interest on public debt
PDI = PI - Personal taxes
Where,
GNP = Gross National Product
NNP = Net National Product
NNI = Net National Income
PI = Personal Income
PDI = Personal Disposable Income

(i) Per Capita income (or) output per person is an indicator to show the living standards of people in a country.
(ii) If real PCI increases.
(iii) It is considered to be an improvement in the overall living standard of people.
(iv) PCI is arrived at by dividing the GDP by the size of population.
(v) It is also arrived by making some adjustment with GDP
(vi) \(PCI=\frac { GDP }{ Total\ number\ of\ people\ in\ a\ country } \) (or)\(PCI=\frac { National\ Income }{ Total\ Population } \)

(i) Accurate and reliable data are not adequate as farm output in the subsistence sector is not completely informed.
(ii) In animal husbandry there are no authentic production data available.
(iii) Different languages, customs, etc., also create problems in computing estimates.
(iv) People in India are indifferent to the official inquiries. They are in most cases non-cooperative also.
(v) Most of the statistical staff are untrained and inefficient.
(vi) Therefore, national income estimates in our country are not very accurate or adequate.