The authors of the papers from this conference attempt to find out whether there are problems in cross-border leasing, and - if that is the case - to find out their roots. Papers discuss situations in which cross-border leases result in double taxation (whether legal or economic) or in tax advantages that would not have occurred in a national lease transaction. In the context of the congress papers, a lease is defined as a contract whereby a separation of the ownership of an asset and its usage is established for a certain period of time. The papers follow a generalised format, starting with a comparative analysis of the tax rules to discover differences in the income tax treatment of leases between different countries, then moving on to international tax rules to see if they create further problems and if the tax treaty network solves these problems or creates new ones. The authors also attempt to discover whether new problems emerge in triangular cases.