Trade union density
Union density or trade union density is the ratio of wage and salary earners that are trade union members to the total number of wage and salary earners in the economy. It is accordingly a standard measure to compare the associational power of trade unions across countries. As with calculating union membership figures, calculating union density is complicated by issues such as the variety of sources (e.g. official administrative data, data provided by individual unions, survey data), as well as the lack of reliable data for some countries.
Net and gross union density
Unlike trade union membership figures, net trade union density rates take into account only those union members that are employed; it therefore excludes union members that are retired, unemployed or student members. Gross trade union density rates, on the other hand, consider all union members, irrespective of whether they are active in the labour market. As such, net and gross trade union density rates provide different information: while the net union density rate constitutes a more accurate approach in terms of the actual power and representation of trade unions in the workforce, the gross union density rate provides information about trade unions’ representation in society.
Decline in union density and cross-national differences
Since the early 1980s, trade union density rates in most EU Member States have been declining, largely due to the growing number of employees who choose not to join a trade union. One major reason for this decline in membership figures is the expansion of non-standard forms of employment. Generally, changes in trade union density rates tend to be more stable than union membership rates, as they incorporate labour market dynamics. For instance, in the context of the recent economic crisis, the decline in union density slowed down due to a strong fall in employment.
There are substantial differences in union density figures across EU Member States. Scandinavian countries exhibit very high and rather stable union density compared to the central and eastern European Member States, where union density is fairly low and declining. There are also marked differences across continental and Mediterranean countries, but a these countries share a common declining trend.
Differences in union density rates between sectors within a country are also very important. Union density tends to be higher in the public sector compared to manufacturing and the private services sector, for example. This is linked to the greater security and better working conditions enjoyed by public sector employees, which counterbalance the potential drawbacks of membership to workers.
Like trade union membership rates, differences in cross-national trade union density rates are affected by factors including institutional considerations – such as the existence of collective bargaining extension mechanisms – as well as what kinds of services are provided and managed by trade unions or the predominant level of collective bargaining. Another important factor is the role played by trade unions in the system of welfare payments, particularly unemployment benefits (also known as the Ghent system).