Income and fertility
Gross domestic product (GDP) is the total dollar value of all goods an economy produces over a given time, usually expressed as a comparison to the previous quarter or year. If the year to year GDP is up 5 percent, then the economy has grown 5 percent. There are two approaches - the income approach (adding up all earnings over a year) and the expenditures approach (adding up what everyone spent). The income approach is described as the total employee compensation, gross profit for corporations and non-incorporated firms, and taxes minus subsidies. The expenditures method is more common and it specifically combines total consumption within households, and the total investment within a business. It also reveals how much money the government is spending and the balance of trade. Another factor by which is not promptly supportive are the youngsters who play a role within GDP. They clearly do not add to it and do not help the stock and bond market returns. Youngsters are wellsprings of advancement, entrepreneurial souls and play a major incentive to GDP.
Penn World Table
A common practice for comparing GDPs across countries has been to use exchange rates. However, this assumes that this relative price - based on traded products - is representative of all relatives prices in the economy, i.e. that it represents the purchasing power parity (PPP) of each currency. By contrast, PWT uses detailed prices within each country for different expenditure categories, regardless of whether the output is traded internationally (say, computers) or not (say, haircuts). These detailed prices are combined into an overall relative price level, typically referred to as the country's PPP. The detailed prices used to compute PPPs are based on data published by the World Bank as part of the International Comparison Program (ICP).