Diversification of financial securities is considered a substantial element of portfolio risk. In this context, the construction of an optimal portfolio is an ongoing concern for portfolio managers. This study measures the risk–reward tradeoffs linked to the stock indexes of Germany, Spain, Italy, France, and England. First, the stock indexes are analyzed as individual portfolios and later compared to the hypothetical common equity index. The results show diversification benefits gained from a hypothetical common European stock market. Individual stock prices and trade volumes are collected weekly from January 1, 2008 to December 31, 2018. The results indicate that, on average, the most well-diversified equity indexes are IBEX35, FTSE MIB, and FTSE100. In contrast, DAX, MDAX, and CAC40 on average tend to be less diversified. The diversification risk for DAX, MDAX, and CAC40 decreases from joining a common hypothetical stock market, while for FTSE100, FTSE MIB, and IBEX it increases.

The research focuses on the impact of value-added tax (VAT) harmonization as necessary to ensure the establishment and functioning of the single market. The aim is to show the legal basis and national actions taken by the nations to fulfill the Directives’ requirement for harmonization as a precondition for promoting the single market. This paper also examines Member States’ (MS) ongoing efforts to harmonize national tax systems because of fiscal sovereignty to choose its own VAT structure which prevents complete harmonization and the European Court of Justice (ECJ) interpretation approach to VAT. An example of a harmonized tax inside the European Union (EU) is VAT. The development and effectiveness of a single market is the EU’s top priority. To realize the goal of creating a single market, all barriers to the free movement of people, capital, goods, and services between the MS must be eliminated (Kollmann, 2019). To fulfill the research aims, the histogram methodology and several statistical analyses were utilized to summarize data and hypothesis testing. The findings underline that, from the MS’s viewpoint, the EU VAT is primarily a significant source of revenue. From the viewpoint of the EU, a harmonized VAT should be seen as a fundamental part of the single market. The research is of particular relevance to researchers, tax practitioners, VAT policy designers, etc. The VAT harmonization process and challenges in the EU are an excellent platform for analyzing the views of science, doctrine, and practice on this issue. This research will enable further research into the strategy and challenges of VAT harmonization.

The aim of this research is to analyze and find out the major issue of tax reforms in selected Balkan Countries and the case of Kosovo. In this analysis we have used the research method of case study. The results of research show that reforms of tax systems of Balkan Countries, including Kosovo, is one of the most important components of their social-economic transition led by the aspiration to become members of the European Union. Higher results consist in the fact that the Balkan countries, some earlier some later, have included Personal Income Tax, Corporate Income Tax and the VAT into their tax systems. In this context, in order to create competitive tax systems to attract investments and to make tax harmonization with the EU, the tax rates have considerably been reduced and successful steps have been taken in the function of harmonization of taxes with the EU member countries. Some countries have managed to build their tax systems in accordance with acquis communautaire. After the declaration of Independence, the Government of the Republic of Kosovo took the first reformation step by reducing the income and corporation income tax rates. However, the taxation system and policies in Kosovo must also be reformed in many other components. Today, when from the start of transition process in the Balkan countries about 26 years have passed, the reformation of their tax system is still ongoing, facing numerous challenges.

The aim of this research is to analyze and find out the major issue of fiscal transparency in theory and practice and the case of Kosovo. In this analysis we have used the research method of case study. The results of research show that are given various definitions from different aspects of transparency in general and of fiscal transparency particularly in financial theory. Nowadays, transparency has been made an indicator of the quality of institutions and credibility of modern states. Frequent social and political changes in Kosovo from 1999 until the second half of 2008, and those that followed them have also had their effects on the management of public finances, budgetary procedure and fiscal transparency. With the declaration of independence of Kosovo and the entry into force of the constitution, de jure, the role of parliament in the budgetary procedure was increased. Despite the achieved results, this analysis points out a lot of deficiencies that are necessary to be addressed in order to increase fiscal transparency in Kosovo. Among other things, transparency should be increased by strengthening the role of parliament in the budgetary procedure.