3. In case of mixed income, a grave problem arises regarding allocation of income among the factors. This makes the task of income among the factors. This makes the task of estimating national income difficult.
4. In case of unorganised sectors, assessment of output is a guess work. This makes the figure for national income unreliable.
5. The greatest difficulty in estimating national income is lack of adequate statistical data.
Statistical data regarding agriculture and allied occupations, household enterprises is not available in most of the developing countries. There is no accurate information available regarding consumption, investment expenditure or savings especially for rural population. All these pose problems in developing countries while calculating national income.
However, in India, it is not possible to measure national income using a single method. As a matter of fact, different methods are being adopted for different sectors. Everything depends upon accuracy of data and the estimation procedure.
We find gaps in computation, statistical information and its systematisation. Therefore, it is necessary to cover up these gaps for more efficient economic planning and social accounting.