Starting from the 21st century, a new phenomenon has discovered in the world economy - a trend has emerged to form a single world closely interconnected economic system. The formation of a closely interconnected system of the world economy is due to the proliferation of new technological structures, the structures of the new post-industrial, information economy. It is confirmed by an estimate of the average values of the coefficient of correlation of the rates of economic growth of 180 countries of the modern world over ten-year periods. The link between the economic growth rates of the countries of the world began to take shape at the beginning of the XXI century, as evidenced by the increase in the correlation coefficient of the economic growth rates of the countries of the modern world to significant values. The impact of the proliferation of new technological structures, new, post-industrial, information economy structures on the formation of a closely interconnected world economy system is confirmed by the estimates of the correlation between the economic growth rates of the USA, EU, Japan, India and China.