Socio-economic development of countries based on the Composite Country Development Index (CCDI)

World experience indicates the existence of significant imbalances in the development of countries. The problem of assessing the rational development of the regional and national economy is becoming urgent, since such assessments can prevent development imbalances across countries. The aim of this study is to elaborate a methodology to assess the countries' socio-economic development by integraring 12 modern indices of socio-economic development into the Composite Country Development Index (CCDI). The methodology of this research was based on a set of key indices that described socio-economic development level in four fields (social development, digital development, economic development, and environmental security) and then these indices were integrated into the CCDI. The study further applied factor analysis and R-Studio software to define the gaps of social and economic development in 59 selected countries using the trigonometric function of the angle sine. The correlation analysis confirmed the existence of a close interrelation among the studied countries. This paper noted that due to the emergence of new priorities, it is necessary to revise the assessment methodology of socio-economic development level and expand them to cover the decisive factors. This was confirmed by the results obtained, demonstrating various combinations of the development level in the four fields and their impact on the CCDI. The scientific contribution of this research is to form a methodology (e.g., the CCDI) for evaluating the socio-economic development level of countries in the world.