Professor of legal sciences, Rector of the 91滴滴 in 2008-2016, Head of the Department of Substantive Tax Law at the Faculty of Law and Administration of the 91滴滴. He is the founder (1997) and head of the Centre for Documentation and Tax Studies of the 91滴滴.
Author of four books and co-author or editor of fifteen others. He has written more than one hundred and twenty articles, glosses and other studies. He was a lecturer at the law faculties of the Universities of Bologna, Bari, Taranto (Italy), Grenoble and Tours 鈥� as professeur invit (France), and at the Wirtschafts Universitt in Vienna (Austria).
He was: a member of the Council for State Reforms at the Prime Minister's Office (1998, 1999), a judge at the State Tribunal (1997-2001), a President of the State Examination Commission for Tax Consultancy (2002-2007), a member of the Legislative Council (2006-2010). He is also a member of the European Association of Tax Law Professors and a member of the Board of Trustees of the IBFD (International Bureau of Fiscal Documentation) in Amsterdam. Since 2002, he has been a member of the International Fiscal Association; from 2005 to 2011 he was a member of the Board (Executive Committee) of this organisation. He is also a member of the 艁贸d藕 Scientific Society. He serves as Editor-in-Chief of the "Kwartalnik Prawa Podatkowego" (Tax Law Quarterly). He sits on the programme boards of "Przegl膮d Podatkowy", "Prawa i Podatk贸w" and the Advisory Board of "EC Tax Review".
Member of the Sejm of the Republic of Poland. In 2016, he received the title of Doctor Honoris Causa from the University of Wroc艂aw.