It is discussed in the article that propensities coud be treated as forces that make statistical regularities stable. It was assumed that theory of propensity may be an important component of the conception of whole - structural approach to phenomenon analysis. Definition of propensity and the whole - structural econometric model was presented. Dependencies between models of all types of statistical regularities were described. It was proved that propensity that makes relations between specified variables for spacial data stable causes that distribution of given variable is also stable. Propensity that makes relations between specific variables for time series stable causes that tendency of analysed variable is stabilized.