The size of undeclared work remains difficult to measure as results considerably vary depending on the concepts and methods used at European and at national levels. In many EU countries the share of the shadow economy in GDP is estimated to be higher than in other developed countries (e.g. Japan, Canada, USA) equalling 18.4 % of GDP in 2012 or EUR 1.87 trillion. Vulnerable groups show the highest involvement in undeclared work (youth, unemployed, persons in a difficult financial situation). • According to research, an effective coping strategy should comprise both, deterrence (control, sanctions) and enabling compliance (e.g. campaigns, information and advice, incentives, amnesties, new job categories). The latter have recently shown a wider take-up, whereas deterrence continues to prevail. Many, but not all responsible national authorities are labour inspectorates. • In April 2014, the Commission proposed the establishment of a European Platform against undeclared work with mandatory membership to build up targeted cooperation of the Member States at EU level; with a particular view towards capacity-building and cross-border cooperation. In its general approach, the Council agreed with most key elements, but included a clause in the recital, stating that it is up to each Member (State) to decide upon the level of involvement. This could become problematic if too many activities are concerned. • The European Parliament, in its 'Resolution on effective labour inspections' of January 2014, called for stronger cooperation and reinforcement of labour inspectorates to fight undeclared work. Apart from a number of European employer organisations, all other stakeholders and committees (social partners, the European Economic and Social Committee and the Committee of Regions) support the creation of an own platform, whilst more would like to be represented as a member or observer in the Platform. • To maximise synergies, structured cooperation of the Platform at European and at national level with all relevant existing European networks will be key; in particular with the Senior Labour Inspectors Committee. To conclude from evaluation, European networks and mutual learning have a real impact. Supportive factors are continuity, ownership, a well-structured work programme, good dissemination and impact evaluation.
