The authors modelled the development of a regional socio-economic situation using static optimization of an unknown function that describes the relationship between the economic parameters of a territorial system. They applied the Bayesian approach to formalize relations, identify optimization parameters, classify the situation of geographically homogeneous economic systems, and describe the transformation of socio-economic regimes. By using variables and coefficients as bilinear characteristics, they reflected the unity of internal and external system properties, as well as the joint effect of geographical and historical economic factors and conditions. The analysis of regional economic indices revealed the empirical dependence of domestic investment on industry and agriculture in the Russian regions in 2000–2016. The results show some patterns of investment and production processes in the Irkutsk region economy in the pre-crisis, crisis, and post-crisis periods. For industrial production, the changes in the investment environment corresponded to 2000–2006, 2006–2008, and 2008–2016. Agricultural production demonstrated no such relationship. Therefore, the geo-economic conditions change the environmental indicators of the regional system that affects the optimal investment solutions made by economic activity subjects.