Abstract
The manuscript aims to assess the scale of shadow economic processes within the non-observed economy, focusing on the self-employment sector, which is insufficiently reflected in national statistics. The research methodology includes an analysis of the conceptual foundations of the shadow economy, decomposition of its components, identification of factors negatively affecting the economy, development of an algorithm for sociological research, and the selection of appropriate models for evaluating the non-observed economy. The study formulates the concept of the shadow economy and shows that shadow business activity in Kazakhstan contributes to income inequality, hidden unemployment, and the exclusion of certain goods and services from official GDP statistics. Using statistical data from 2005 to 2024 and applying methods such as system and statistical analysis, modeling approaches, and the MIMIC (Multiple Indicator Multiple Cause) and DGE (Dynamic General Equilibrium) models, the study estimates the size of the shadow sector. The results reveal insufficient statistical data on shadow activities within self-employment and SMEs. The study concludes that the most reliable assessment of the shadow economy requires an integrated methodological approach, including targeted sociological research and models that account for the influence of multiple factors on informal self-employment.