Calculation of GDP

You asked

Can you please give me details on how you calculate GDP including:

1. How do you define "output"? Is building a new house output? What about selling an existing house, is that output?

2. Where do you get data on expenditure? What about goods purchased from abroad? E.g. If I buy a phone from US would that count towards GDP? What about goods sold directly from person to person, e.g. on a car boot sale or garage sale?

3. How do you measure income? What type of income is included? Is capital gains income included? What about "cash-in-hand" jobs?

4. When all the data is gathered what do you do to it to arrive at the GDP figure?

We said

Full response to GDP questions are provided in the attached Excel worksheet.