The GDP calculation is definitely an arduous process, moreso in developing nations like India where so many statistical assumption we make. GDP serves as denominator in so many Public statics like Debt to GDP Ratio.
Europeans are overhauling there nation accounts, which revealing the economies to be bigger that earlier reckoned.
European countries are adopting new global standards for what counts as output. These replace rules dating back to 1995, when the internet age had barely begun. By far the biggest change in how output is measured will come from reclassifying research and development (R&D). By treating it as an investment, rather than as if it is being consumed in the course of production, it will add to GDP.