Against the backdrop of the debate over the introduction of a fi nancial transaction tax (FTT) in the European Union, this Forum is dedicated to the discussion of issues concerning the implementation and impact of such a tax on the fi nancial sectors of the member states. Dorothea Schäfer regards as the main policy goal of an FTT to be the prospect of slowing down the mutually reinforcing and growing trends of an increasing number of derivative products and shorter holding periods. The FTT can therefore make an important contribution to preventing the decoupling of financial markets from the real economy. The paper by Stephan Schulmeister discusses the essential features of a general FTT that will ensure that the more short-term oriented and riskier a transaction is, the greater the effect of the FTT on transaction costs. John Vella identifies some commonly made claims about an FTT which are of questionable foundation and compares the FTT with some alternative taxes on the financial sector. Donato Masciandaro and Francesco Passarelli focus on how an FTT measure aimed at reducing fi nancial systemic risk can cause political distortions, leading to inefficient and ineffective policies. Finally, the paper by Ross Buckley analyses common myths, inaccuracies and untruths about the EU's proposed FTT.