Increasing the use of renewable energy sources is one of the strategic objectives of the European Union. In this regard, it seems necessary to answer the question: which of the member countries are the most effective in its implementation? Therefore, the main goal was to distinguish groups of European Union countries, including the Visegrad Group, differing in the use of renewable energy sources in transport, electricity, heating and cooling (based on cluster analysis). All members of the EU were determinedly selected for research on 1 February 2020 (27 countries). The research period embraced the years 2009–2019. The sources of materials were the literature on the topic and data from Eurostat. Descriptive, tabular, graphical methods and cluster analysis were used in the presentation and analysis of materials. In 2019 wind and hydro power accounted for two-thirds of the total electricity generated from renewable sources. In 2019, renewable energy sources made up 34% of gross electricity consumption in the EU-27. Wind and hydro power accounted for two-thirds of the total electricity generated from renewable sources (35% each). Moreover, it was determined that there were 5 clusters that differed in their use of renewable energy sources. The highest average renewable energy consumption in transport, heating and cooling in 2019 was characterized by a cluster consisting of Sweden and Finland. In contrast, the highest average renewable energy consumption in electricity was characterized by a cluster consisting of countries such as: Austria, Croatia, Denmark, Latvia and Portugal. Finally, in a group that included countries such as Belgium, France, Luxembourg, Malta, the Netherlands and the entire VG (Hungary, Czechia, Slovakia and Poland), renewable energy consumption rates (in transport, electricity, heating and cooling) were lower than the EU average (27 countries).

This article aims to give an overview of tourism at the time of the global crisis caused by the COVID-19 pandemic. In order to assess the influence of the COVID-19 pandemic on European countries, the Systemic Literature Review (SLR) as well as Our World in Data (2021) and EUROSTAT (2021) secondary data were used. In order to group countries with respect to changes taking place in tourism, Ward’s cluster analysis was applied. After verifying the available data, 31 European countries were eventually selected for the analysis. The application of Ward’s method led to four groups of countries being created that are most similar in terms of changes in the tourism sector between 2019 and 2020. The first cluster comprised eight countries with the highest average rate of restrictiveness. On the other hand, this group recorded the lowest rate of changes concerning arrivals by air transport, which was on average 70.32%. The second group comprised 13 countries. In this cluster, the average change in the number of overnight stays and arrivals at tourist resorts was the lowest in comparison with other clusters. The third cluster comprised four countries where the change in arrivals by air transport was the highest, with an average decrease of 81.76%. The fourth group comprised six countries. The average change in the occupancy of hotel rooms and similar overnight accommodation facilities, as well as arrivals at tourist resorts, was the highest in comparison with other clusters. In addition, the countries were characterized by a relatively high decrease in the number of arrivals by air transport, but a relatively low average rate of restrictiveness.

The main aim of this study is to present a systematic literature review (SLR) of the sustainable energy development (SED) and emphasize important activities relevant to this concept. The following set of research tasks was adopted to achieve the main aim: (1) presentation of the distribution of articles by year (both journal and conference papers) on the SED concept; (2) identification of the most frequently cited articles on the SED concept; (3) identification of the countries that have contributed most to the development of the SED concept through publication activities; (4) demonstration of the subject areas most frequently associated with the SED concept; (5) presentation of the various definitions of the SED; (6) identification of the most important activities carried out under the SED; and (7) presentation of future research directions for the SED. It is worth noting that the research tasks undertaken will be both quantitative and qualitative. The data search was conducted on 31 August 2022, and the selected peer-reviewed database was Scopus. The exclusion process resulted in a total of 607 journal and conference papers. The most important conclusion to be derived from this study is that there is no one unified definition of the SED. Moreover, three activities must be undertaken to realize the SED concept: (1) increasing the use of renewable energy sources in the energy mix, (2) enhancing energy efficiency, and (3) reducing emissions of greenhouse gases and air pollutants. The article also presents the authors’ conceptual model that can serve as a starting point for further analyses in this area.

Higher education is a form of a merit good. This is why governments usually support the delivery of this good. However, one could doubt the efficiency of such solution. How well do public higher education institutions (HEIs) do their job? How to measure their performance? This paper discusses these issues. First, we discuss the problem of defining and measuring efficiency in the case of publicly held HEIs with particular emphasis put on the Data Envelopment Analysis (DEA) method. Secondly, we present the results of our empirical investigation of efficiency assessed using the DEA method conducted on the sample of 33 Poland faculties specialized in social sciences . We use Charnes-Cooper-Rhodes (CCR) output oriented model with two inputs and three outputs. Next, we present some important differences in efficiency of those faculties. We also define benchmarks for inefficient HEIs and quantify the gaps to be fulfilled by them in order to become efficient. Finally, we pinpoint the directions of further research.

The aim of this paper is to present the involvement of public Higher Education Institutions (HEIs) in Poland in promoting the Sustainable Development Goals (SDGs) in 2021. The reason for undertaking the research was a noticeable lack of studies in the literature on the engagement of universities in the concept of sustainability. The research conducted was mainly qualitative in nature. The aim was realized using three groups of research methods: collection of empirical data, data processing, and the presentation of study outcomes. The study used 16 indicators, constructed from data taken from SciVal and RAD-on reports. These indicators presented the number of publications promoting each of the SDGs in 2021 per academic staff and other persons carrying out and participating in teaching or research activities. The research was conducted on 57 universities from Poland. Four clusters were distinguished as a result of the cluster analysis that was performed. The first cluster comprised only universities of life sciences. This group had the highest publication productivity for the following goals: SDG2, SDG3, SDG6, SDG11, SDG12, SDG13, SDG14, SDG15, and SDG16. The universities that made up cluster 2 (predominantly universities of technology) specialized in publications related to goals such as SDG7 and SDG9. The highest publication productivity for SDG1, SDG4, SDG5, SDG8, SDG10, and SDG16 belonged to cluster 3 (consisting mainly of universities of economics). The HEIs (mainly universities of physical education) that made up cluster 4 did not have the highest publication productivity in any of the SDGs. Therefore, it can be concluded that, in 2021, there was a correlation between the profile of a public HEI in Poland and the SDGs it was involved in promoting.

The aim of this article was to estimate the total efficiency of teaching activity carried out in Polish higher education institutions in 2015. The study used the EBM model belonging to the nonparametric DEA method. The output of the education process was measured by the number of graduates of the first-cycle and second-cycle studies and long-cycle studies, the number of doctoral degrees awarded, the number of postgraduate studies certificates issued, and the number of academic teachers and the total value of teaching activity revenue, the total value of state budget subsidies along with fees for educational services and fixed assets. Efficiency measurement was made for two variants: M1 and M2. The obtained research results indicate that on average, the difference between the indicators of the total efficiency of teaching activity under the two empirical models is 0.00. This is due to the fact that the share of budget subsidies and fees paid by students of part-time studies, in the revenues from teaching activity is at the level of 87%. There is also a positive but weak correlation between the total efficiency ratios and financial results obtained from teaching activities.