Growing income inequality currently poses a significant threat to sustainable development. Hence, it is important to monitor this phenomenon, in particular to identify determinants favouring the deepening of income inequality. One of the significant determinants in this respect is the declining labour income share in national income. The theoretical justification of the presumption of a negative relationship between the share of labour in the national income and income inequality has strong logical foundations. Existing studies indicate, however, some ambiguities as to the strength of this relationship and the existence of various factors cancelling this relationship. The following study attempts to verify the existence, direction, and intensity of the relationship between the labour income share and income inequality in a relatively homogeneous group of 33 OECD countries studied in 1990–2018. The main hypothesis verified in the study is the assumption that there is a negative relationship between labour share and income inequality. Our results show that the relationship between the share of employees’ and self-employed workers’ income in the national income and income inequality at the general level (i.e., in a group study of 33 countries in total) exists, is negative and statistically significant, but has a very small share in explaining the behaviour of income inequality.

Inclusive development is a multifaceted conception, which makes it difficult to measure. Recent years, however, have brought some proposals for measuring this phenomenon, which opens up new opportunities to deepen the knowledge of how countries are doing in making their economic and social progress more inclusive. The aim of the paper is to examine the level of advancement of inclusive development in Poland in comparison to other OECD countries. The main hypothesis states that the development in Poland is less inclusive than the OECD average. The research covers data from 30 countries (OECD members, excluding the countries where such data were unavailable), and is based on the OECD’s proposal of measurement. The study was conducted with the use of data normalisation into unified indices, taxonomic methods (cluster analysis based on the Ward hierarchic method), and comparative analysis. The results indicate areas of improvement for Poland. These are issues connected with the functioning of the labour market (the level of labour productivity, employment ratio, earnings dispersion), access to loans for starting or expanding businesses, but also life expectancy, wealth distribution, early childhood education and care, and, most of all, characteristics related to the area of governance, such as trust in the government, and voter turnout.