The spectacular surge of Poland's VAT revenues after 2015 prompted a discussion about the role of the tax administration in collecting tax liabilities. Unfortunately, the scarcity of the available data prevents empirical studies from reaching reliable conclusions about the determinants of VAT revenues. Given that, this article presents a wider attempt at identifying the determinants of VAT revenues in the EU Member States. Using panel cointegration methods, several working hypotheses linking VAT gap to income factors, the business cycle, tax carousels, and an effectiveness of the government are evaluated. The results of the research provide evidence that the VAT gap in the EU countries is under a strong influence from variables approximating changes in per capita incomes, the business cycle, and the openness of an economy to intra-EU trade. The latter finding is a sufficient indication that the improvements made to Poland's tax system were both legitimate and effective.

A review of the contemporary mainstream literature on exchange rate modelling clearly indicates that the rational expectations hypothesis (RE) is almost invariably taken as a point of reference in empirical investigations. This paper tests the RE hypothesis for the Polish foreign exchange market within the Roman Frydman and Michael Goldberg model that builds on the hypothesis of imperfect knowledge economics (IKE). The employed modelling strategy consists in the formulation of assumptions about the persistence of nominal rate, prices and interest rates and of the verification of competing scenarios congruent with RE and IKE. As a result of the analysis, the RE hypothesis is rejected in favour of the IKE alternative.

The abrupt depreciation of the zloty during the subprime crisis and fastrising prices are serious problems, because Poland, having to fulfil five Maastricht criteria, makes the dependence of her domestic inflation on price increases in the EU countries the central point of the discussion about the optimal monetary and fiscal policy rules for the next few years. The primary objective of the paper is to test out some hypotheses about the main sources of the volatility of the Polish zloty / euro exchange rate and inflation in Poland. Because several competing theoretical models describing inflationary processes are widely used, special attention is paid to their empirical verification. The working-hypotheses allowing for the country-specific features of the consumer and producer price inflation are formulated and verified in the paper.

Foreign direct investment (FDI) and foreign portfolio investment (FPI) have been long considered as independent forms of international capital flows. This paper analyzes the mutual relationship between FDI and FPI and attempts to answer the question whether they complement or substitute for each other from a foreign investor’s point of view. The paper describes the main characteristics of FDI and FPI in terms of their volatility and profitability. We analyze the long-run and short-run relationships between FDI and FPI using vector error correction (VEC) regressions on data for Poland as it is the largest country in Central and Eastern Europe and receives the lion’s share of these two forms of capital in the region. Our investigation suggests that FDI and FPI may be regarded as substitutes. In economically stable periods FDI tends to dominate over FPI but during insecurity and economic distress FPI starts to gain importance.