Young people experience the highest level of unemployment and, even when in employment, they register the highest level of labour market outsiderness, compared to adults. Institutions could play a pivotal role in increasing the level of social justice for youth, promoting their condition in the labour market. Traditionally, the institution aimed at representing and promoting workers' interests is the trade union, but evidence shows, paradoxically, difficulties of trade unions in getting in contact with the most vulnerable workers - youth - mostly due to youth labour market structural characteristics. Since workers decision of joining a union comes later in the (working) life (as evident by the age distribution of trade unions' members) it remains unclear if youth membership has to be included (or not) among trade unions’ strategic priorities. In the wave of increasing digital interaction between citizens and social institutions and the increasing use of social media as research tool in social sciences, the aim of this research is to stress, by using Twitter as a unique source of data, first, the extent to which trade unions are at the centre of debate, compared to theoretically similar institutions and, second, the extent to which trade unions interact with or speak about youth in six countries: Belgium, Germany, Italy, the Netherlands, Spain and the UK. Results show that social media discussions referring to "trade unions" is lower than for other similar socio-political institutions, this being true in all six languages analysed in a random month. Moreover, notwithstanding the fact that trade unions in the analysed countries are all formally present on Twitter, interaction with different institutions, and in particular with the youth sphere is limited and mostly done by trade unions’ youth groups, while most communication flows of national trade unions are rather “auto-referential”, i.e. mostly referring to the trade union itself. Analysing (up to) 3.200 tweets written by each of the national trade unions, only a small part (3% on average) is directed to (or concerns) youth. When looking at the Twitter accounts of trade unions youth groups (when existent), youth are of course more at the centre of communications (32% on average). These results may suggest the fact that youth are, in practice, considered as a topic that is out of national trade unions' ordinary agenda and daily business, falling instead mostly in trade unions' youth specific group business, and thus supporting the hypothesis that youth membership is not specifically addressed by trade unions at the national level, especially in those countries where no specific youth department of unions exists.
