Answer given by Mr Avramopoulos on behalf of the Commission
1. As outlined in a report of the United States (US) Congressional Research Service of 11 December 2015, the following EU Member States are VWP (Visa Waiver Program) Countries: Austria, Belgium, the Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, the Netherlands, Portugal, Slovakia, Slovenia, Spain and the United Kingdom. This report also indicates the existing arrangements on information exchange.2. Within the EU, the following EU instruments allow for the exchange of same or similar information between Member States: Decision 2005/671/JHA of 20 September 2005 on the exchange of information and cooperation concerning terrorist offences; Framework Decision 2006/960/JHA of 18 December 2006 on simplifying the exchange of information and intelligence between law enforcement authorities of the Member States of the European Union; Decision 2008/615/JHA of 23 June 2008 on the stepping up of cross-border cooperation, particularly in combating terrorism and cross-border crime (the ‘Prüm’ Decision), and Framework Decision 2008/977/JAI of 27 November 2008 on the protection of personal data processed in the framework of police and judicial cooperation in criminal matters.3. The Commission is not in a position to quantify the information shared on a mandatory basis between the US and the EU (and its Member States) and that shared between EU Member States.
-  https://www.fas.org/sgp/crs/homesec/RL32221.pdf