He was a doctor of philosophical sciences (dissertation on the methodological and procedural issues of sociological research of the influence of the scientific technological revolution on personality directedness of an industrial worker; defended in Kyiv in 1987).
In 1992, on the basis of this Center, he co-founded, together with Volodymyr Paniotto and Michael Swafford, Kiev International Institute of Sociology and became its President.
In the field of macrosociology, he forecasted that information production would become the dominant production type [1], suggested that socio-genesis was complete when there appear beings capable of creating symbolic systems [2], developed a theory of historical changes of a macrostructure dominant of society reproduction processes [3-6], analyzed Russian-Ukrainian linguistic and ethnic as well as bi-ethnic heterogeneity of ethno-national structures of Ukrainian regions [9, 16, 19].
As stated by Volodymyr Paniotto, Khmelko's close colleague, in one of his early articles, Khmelko suggested a theory of dominant production types that foreran the key idea of the well-known Alvin Toffler's work "Third Wave".
[2] The latest study, conducted by Valery Khmelko, was "Analysis of social factors of predominance of pro-European or pro-Russian geopolitical orientations in the regions of Ukraine."