The World in economic indices depending on a country's size. I. The World on the {Population, GDP}-plane

The purpose of the study is to develop a method and conceptual apparatus for identifying the distribution structure of countries on the {Population, GDP}-plane. To achieve this goal, two new economic indexes have been introduced: the "product index" PI and the "demographic index" DI. With the help of an identity linking the indices PI and DI for each country with the economic productivity index EPI, the existence of a global economic parameter – the critical value of the economic productivity index EPIc, was revealed. The economic meaning of this global parameter is revealed. The scientific novelty of the research lies in the development of a two-dimensional interval classification of states according to the scale of the economy and the scale of the country. The use of this classification reveals, as a result, fundamental features of the distribution of countries on the plane {Population, GDP}, deeply rooted in world history and slowly changing in time.