The analysis aims to identify spatial variations of socio-economic development in Poland at the local level and to determine their correlation with conditions resulting from the historical political divisions of today’s areas of the country. The research procedure helps to verify the hypothesis that spatial differentiation of socio-economic development in Poland is permanent and does not show significant changes during periods of economic growth and crisis. We can emphasize at the same time the persisting differences between cities and their functional areas on the one hand and rural areas on the other. The study applied an innovative procedure of determining the synthetic index. The procedure of classifying local units presented in the text was based on the original random forest method. The outcomes confirm that contemporary spatial diversification at the level of socio-economic development in Poland is still strongly conditioned by history, especially by the socio-economic consequences of the partition of Poland between the three superpowers (Russia, Prussia and Austria). This is evident in the synthetic presentation of the level of socio-economic development. However, in the case of certain socio-economic phenomena, the values of indicators describing them no longer directly relate in their diversity to historical borders, particularly the former partition borders.

There is now a renaissance of interest in Poland’s urban regions, including the Functional Urban Areas (FUAs) and this can be considered due to a change from the administrative and sectoral approach dominating planning for regional development in the direction of a functional one. This paper presents an overview of the concepts related to FUAs and related issues, as well as methods referred to in the Polish literature when it comes to the delimitation of urban-related areas. It then goes on to propose a new delimitation of urban functional areas extending to the entire territory of the country. FUAs were delimited as nodal regions on the basis of a criterion of functional linkage – commuting and migration exchange (population check-in and check-out), using the additional criterion of maximum temporal distance. The results of the prepared means of drawing distinctions showed how the daily life of Poland's population is organised in relation to a relatively large number of diverse "micro-regions." The number of classified FUAs (413) is similar to the number of county-level administrative units known as poviats (380), while these units are characterised by different sizes and spatial extents. The work is in line with the demand for those engaging in spatial and strategic planning to think in terms of functional areas.

The paper develops a spatial agglomeration index (SPAG) of the economic activity for the point geo-localizations of firms. It includes the effects of location, the distance between firms and the overlapping impact of the firms' size. The SPAG builds a new class of measures of the spatial density of the economic activity inside the region, based on the geometrical representation of firms with circles, without referring to the commonly used Ripley's K function. The SPAG measures the degree of divergence from the benchmark distribution, what detects different spatial distributions as clusters or borderline dispersion. We test SPAG with real point data.