State with reasons, whether you agree or disagree with the following statements

1. There are many theoretical difficulties in the measurement of national income.
Ans: Yes, I Agree with the above statements: 
Reason: 
a. There are many theoretical difficulties in the measurement of national income for examples,
b. Transfer payments, Illegal income, Unpaid services, production for self-consumption and so many.

2. Under the output method, a value-added approach is used to avoid double counting.
Ans: Yes, I Agree with the above statements: –
Reason:
a. In order to avoid double-counting, a value-added approach is used. According to this approach, the value-added at each stage of the production process is included. 
b. The difference between the value of final outputs and inputs, at each stage of production, is called the value-added